diff --git a/.github/scripts/rename/include.sh b/.github/scripts/rename/include.sh
new file mode 100755
index 0000000000..fbf165b975
--- /dev/null
+++ b/.github/scripts/rename/include.sh
@@ -0,0 +1,30 @@
+#!/bin/bash
+
+# Exit the script as soon as an error occurs.
+set -e
+
+# This script checks whether there are no new include guards introduced by a new
+# PR, as header files should use "#pragma once" instead. The script assumes any
+# include guards will use "XRPL_" as prefix.
+# Usage: .github/scripts/rename/include.sh <repository directory>
+
+if [ "$#" -ne 1 ]; then
+    echo "Usage: $0 <repository directory>"
+    exit 1
+fi
+
+DIRECTORY=$1
+echo "Processing directory: ${DIRECTORY}"
+if [ ! -d "${DIRECTORY}" ]; then
+    echo "Error: Directory '${DIRECTORY}' does not exist."
+    exit 1
+fi
+
+find "${DIRECTORY}" -type f \( -name "*.h" -o -name "*.hpp" -o -name "*.ipp" \) | while read -r FILE; do
+    echo "Processing file: ${FILE}"
+    if grep -q "#ifndef XRPL_" "${FILE}"; then
+      echo "Please replace all include guards by #pragma once."
+      exit 1
+    fi
+done
+echo "Checking complete."
diff --git a/.github/workflows/reusable-check-rename.yml b/.github/workflows/reusable-check-rename.yml
index af55084405..a73ac49b7d 100644
--- a/.github/workflows/reusable-check-rename.yml
+++ b/.github/workflows/reusable-check-rename.yml
@@ -31,6 +31,8 @@ jobs:
         run: .github/scripts/rename/namespace.sh .
       - name: Check config name
         run: .github/scripts/rename/config.sh .
+      - name: Check include guards
+        run: .github/scripts/rename/include.sh .
       - name: Check for differences
         env:
           MESSAGE: |
diff --git a/include/xrpl/basics/Archive.h b/include/xrpl/basics/Archive.h
index 84af8a7c7d..58e12bbb71 100644
--- a/include/xrpl/basics/Archive.h
+++ b/include/xrpl/basics/Archive.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_ARCHIVE_H_INCLUDED
-#define XRPL_BASICS_ARCHIVE_H_INCLUDED
+#pragma once
 
 #include <boost/filesystem.hpp>
 
@@ -16,5 +15,3 @@ void
 extractTarLz4(boost::filesystem::path const& src, boost::filesystem::path const& dst);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/BasicConfig.h b/include/xrpl/basics/BasicConfig.h
index 9aa7f3e612..d18019fa9f 100644
--- a/include/xrpl/basics/BasicConfig.h
+++ b/include/xrpl/basics/BasicConfig.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_BASICCONFIG_H_INCLUDED
-#define XRPL_BASICS_BASICCONFIG_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/contract.h>
 
@@ -369,5 +368,3 @@ get_if_exists<bool>(Section const& section, std::string const& name, bool& v)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/Blob.h b/include/xrpl/basics/Blob.h
index 986f829371..ee0d6cf3b5 100644
--- a/include/xrpl/basics/Blob.h
+++ b/include/xrpl/basics/Blob.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_BLOB_H_INCLUDED
-#define XRPL_BASICS_BLOB_H_INCLUDED
+#pragma once
 
 #include <vector>
 
@@ -11,5 +10,3 @@ namespace xrpl {
 using Blob = std::vector<unsigned char>;
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/Buffer.h b/include/xrpl/basics/Buffer.h
index b7e0878477..5192daf632 100644
--- a/include/xrpl/basics/Buffer.h
+++ b/include/xrpl/basics/Buffer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_BUFFER_H_INCLUDED
-#define XRPL_BASICS_BUFFER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Slice.h>
 #include <xrpl/beast/utility/instrumentation.h>
@@ -213,5 +212,3 @@ operator!=(Buffer const& lhs, Buffer const& rhs) noexcept
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/ByteUtilities.h b/include/xrpl/basics/ByteUtilities.h
index 88bb297346..cd10611a50 100644
--- a/include/xrpl/basics/ByteUtilities.h
+++ b/include/xrpl/basics/ByteUtilities.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_BYTEUTILITIES_H_INCLUDED
-#define XRPL_BASICS_BYTEUTILITIES_H_INCLUDED
+#pragma once
 
 namespace xrpl {
 
@@ -20,5 +19,3 @@ megabytes(T value) noexcept
 static_assert(kilobytes(2) == 2048, "kilobytes(2) == 2048");
 static_assert(megabytes(3) == 3145728, "megabytes(3) == 3145728");
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/CompressionAlgorithms.h b/include/xrpl/basics/CompressionAlgorithms.h
index 52dc406d5d..b8fe4c8018 100644
--- a/include/xrpl/basics/CompressionAlgorithms.h
+++ b/include/xrpl/basics/CompressionAlgorithms.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_COMPRESSIONALGORITHMS_H_INCLUDED
-#define XRPL_COMPRESSIONALGORITHMS_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/contract.h>
 
@@ -133,5 +132,3 @@ lz4Decompress(InputStream& in, std::size_t inSize, std::uint8_t* decompressed, s
 }  // namespace compression_algorithms
 
 }  // namespace xrpl
-
-#endif  // XRPL_COMPRESSIONALGORITHMS_H_INCLUDED
diff --git a/include/xrpl/basics/CountedObject.h b/include/xrpl/basics/CountedObject.h
index e464e470af..55a895dbb1 100644
--- a/include/xrpl/basics/CountedObject.h
+++ b/include/xrpl/basics/CountedObject.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_COUNTEDOBJECT_H_INCLUDED
-#define XRPL_BASICS_COUNTEDOBJECT_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/type_name.h>
 
@@ -134,5 +133,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/DecayingSample.h b/include/xrpl/basics/DecayingSample.h
index 3b5e947f1f..e4c9ad5d7a 100644
--- a/include/xrpl/basics/DecayingSample.h
+++ b/include/xrpl/basics/DecayingSample.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_DECAYINGSAMPLE_H_INCLUDED
-#define XRPL_BASICS_DECAYINGSAMPLE_H_INCLUDED
+#pragma once
 
 #include <chrono>
 #include <cmath>
@@ -130,5 +129,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/Expected.h b/include/xrpl/basics/Expected.h
index 9ce771dc23..7c98e72107 100644
--- a/include/xrpl/basics/Expected.h
+++ b/include/xrpl/basics/Expected.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_EXPECTED_H_INCLUDED
-#define XRPL_BASICS_EXPECTED_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/contract.h>
 
@@ -229,5 +228,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif  // XRPL_BASICS_EXPECTED_H_INCLUDED
diff --git a/include/xrpl/basics/FileUtilities.h b/include/xrpl/basics/FileUtilities.h
index 03013da63a..299269703a 100644
--- a/include/xrpl/basics/FileUtilities.h
+++ b/include/xrpl/basics/FileUtilities.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_FILEUTILITIES_H_INCLUDED
-#define XRPL_BASICS_FILEUTILITIES_H_INCLUDED
+#pragma once
 
 #include <boost/filesystem.hpp>
 #include <boost/system/error_code.hpp>
@@ -18,5 +17,3 @@ void
 writeFileContents(boost::system::error_code& ec, boost::filesystem::path const& destPath, std::string const& contents);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/IntrusivePointer.h b/include/xrpl/basics/IntrusivePointer.h
index 366392885b..4464c37dc5 100644
--- a/include/xrpl/basics/IntrusivePointer.h
+++ b/include/xrpl/basics/IntrusivePointer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_INTRUSIVEPOINTER_H_INCLUDED
-#define XRPL_BASICS_INTRUSIVEPOINTER_H_INCLUDED
+#pragma once
 
 #include <concepts>
 #include <cstdint>
@@ -485,4 +484,3 @@ dynamic_pointer_cast(TT const& v)
 }
 }  // namespace intr_ptr
 }  // namespace xrpl
-#endif
diff --git a/include/xrpl/basics/IntrusivePointer.ipp b/include/xrpl/basics/IntrusivePointer.ipp
index 85eda5cb16..d52aa6299f 100644
--- a/include/xrpl/basics/IntrusivePointer.ipp
+++ b/include/xrpl/basics/IntrusivePointer.ipp
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_INTRUSIVEPOINTER_IPP_INCLUDED
-#define XRPL_BASICS_INTRUSIVEPOINTER_IPP_INCLUDED
+#pragma once
 
 #include <xrpl/basics/IntrusivePointer.h>
 #include <xrpl/basics/IntrusiveRefCounts.h>
@@ -703,4 +702,3 @@ SharedWeakUnion<T>::unsafeReleaseNoStore()
 }
 
 }  // namespace xrpl
-#endif
diff --git a/include/xrpl/basics/IntrusiveRefCounts.h b/include/xrpl/basics/IntrusiveRefCounts.h
index e9214a5adc..0273ed4647 100644
--- a/include/xrpl/basics/IntrusiveRefCounts.h
+++ b/include/xrpl/basics/IntrusiveRefCounts.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_INTRUSIVEREFCOUNTS_H_INCLUDED
-#define XRPL_BASICS_INTRUSIVEREFCOUNTS_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/instrumentation.h>
 
@@ -461,4 +460,3 @@ partialDestructorFinished(T** o)
 //------------------------------------------------------------------------------
 
 }  // namespace xrpl
-#endif
diff --git a/include/xrpl/basics/KeyCache.h b/include/xrpl/basics/KeyCache.h
index 038bf7b9b7..4f2ca20cca 100644
--- a/include/xrpl/basics/KeyCache.h
+++ b/include/xrpl/basics/KeyCache.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_KEYCACHE_H
-#define XRPL_BASICS_KEYCACHE_H
+#pragma once
 
 #include <xrpl/basics/TaggedCache.h>
 #include <xrpl/basics/base_uint.h>
@@ -9,5 +8,3 @@ namespace xrpl {
 using KeyCache = TaggedCache<uint256, int, true>;
 
 }  // namespace xrpl
-
-#endif  // XRPL_BASICS_KEYCACHE_H
diff --git a/include/xrpl/basics/LocalValue.h b/include/xrpl/basics/LocalValue.h
index 8c664116c3..94af41a41d 100644
--- a/include/xrpl/basics/LocalValue.h
+++ b/include/xrpl/basics/LocalValue.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_LOCALVALUE_H_INCLUDED
-#define XRPL_BASICS_LOCALVALUE_H_INCLUDED
+#pragma once
 
 #include <boost/thread/tss.hpp>
 
@@ -107,5 +106,3 @@ LocalValue<T>::operator*()
         lvs->values.emplace(this, std::make_unique<detail::LocalValues::Value<T>>(t_)).first->second->get());
 }
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/Log.h b/include/xrpl/basics/Log.h
index 92fd2c0e9c..786fbc5da2 100644
--- a/include/xrpl/basics/Log.h
+++ b/include/xrpl/basics/Log.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_LOG_H_INCLUDED
-#define XRPL_BASICS_LOG_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/UnorderedContainers.h>
 #include <xrpl/beast/utility/Journal.h>
@@ -258,5 +257,3 @@ beast::Journal
 debugLog();
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/MathUtilities.h b/include/xrpl/basics/MathUtilities.h
index bd8ea883fb..4552b335e1 100644
--- a/include/xrpl/basics/MathUtilities.h
+++ b/include/xrpl/basics/MathUtilities.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_MATHUTILITIES_H_INCLUDED
-#define XRPL_BASICS_MATHUTILITIES_H_INCLUDED
+#pragma once
 
 #include <algorithm>
 #include <cassert>
@@ -45,5 +44,3 @@ static_assert(calculatePercent(50'000'001, 100'000'000) == 51);
 static_assert(calculatePercent(99'999'999, 100'000'000) == 100);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/Number.h b/include/xrpl/basics/Number.h
index cdd971d8b0..c269d27781 100644
--- a/include/xrpl/basics/Number.h
+++ b/include/xrpl/basics/Number.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_NUMBER_H_INCLUDED
-#define XRPL_BASICS_NUMBER_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/instrumentation.h>
 
@@ -819,5 +818,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif  // XRPL_BASICS_NUMBER_H_INCLUDED
diff --git a/include/xrpl/basics/RangeSet.h b/include/xrpl/basics/RangeSet.h
index ee95577271..f6e03cac79 100644
--- a/include/xrpl/basics/RangeSet.h
+++ b/include/xrpl/basics/RangeSet.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_RANGESET_H_INCLUDED
-#define XRPL_BASICS_RANGESET_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/core/LexicalCast.h>
 
@@ -173,5 +172,3 @@ prevMissing(RangeSet<T> const& rs, T t, T minVal = 0)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/Resolver.h b/include/xrpl/basics/Resolver.h
index b66f4a5ed5..5bfa6796d2 100644
--- a/include/xrpl/basics/Resolver.h
+++ b/include/xrpl/basics/Resolver.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_RESOLVER_H_INCLUDED
-#define XRPL_BASICS_RESOLVER_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/net/IPEndpoint.h>
 
@@ -45,5 +44,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/ResolverAsio.h b/include/xrpl/basics/ResolverAsio.h
index f2a3da0d58..d0dcc9f185 100644
--- a/include/xrpl/basics/ResolverAsio.h
+++ b/include/xrpl/basics/ResolverAsio.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_RESOLVERASIO_H_INCLUDED
-#define XRPL_BASICS_RESOLVERASIO_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Resolver.h>
 #include <xrpl/beast/utility/Journal.h>
@@ -18,5 +17,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/SHAMapHash.h b/include/xrpl/basics/SHAMapHash.h
index eb635b516c..22f8505912 100644
--- a/include/xrpl/basics/SHAMapHash.h
+++ b/include/xrpl/basics/SHAMapHash.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_SHAMAP_HASH_H_INCLUDED
-#define XRPL_BASICS_SHAMAP_HASH_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/base_uint.h>
 #include <xrpl/basics/partitioned_unordered_map.h>
@@ -98,5 +97,3 @@ extract(SHAMapHash const& key)
 }
 
 }  // namespace xrpl
-
-#endif  // XRPL_BASICS_SHAMAP_HASH_H_INCLUDED
diff --git a/include/xrpl/basics/SharedWeakCachePointer.h b/include/xrpl/basics/SharedWeakCachePointer.h
index 49369265eb..afc701ed5a 100644
--- a/include/xrpl/basics/SharedWeakCachePointer.h
+++ b/include/xrpl/basics/SharedWeakCachePointer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_SHAREDWEAKCACHEPOINTER_H_INCLUDED
-#define XRPL_BASICS_SHAREDWEAKCACHEPOINTER_H_INCLUDED
+#pragma once
 
 #include <memory>
 #include <variant>
@@ -113,4 +112,3 @@ private:
     std::variant<std::shared_ptr<T>, std::weak_ptr<T>> combo_;
 };
 }  // namespace xrpl
-#endif
diff --git a/include/xrpl/basics/SharedWeakCachePointer.ipp b/include/xrpl/basics/SharedWeakCachePointer.ipp
index eeb1a1927b..6e7514ffae 100644
--- a/include/xrpl/basics/SharedWeakCachePointer.ipp
+++ b/include/xrpl/basics/SharedWeakCachePointer.ipp
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_SHAREDWEAKCACHEPOINTER_IPP_INCLUDED
-#define XRPL_BASICS_SHAREDWEAKCACHEPOINTER_IPP_INCLUDED
+#pragma once
 
 #include <xrpl/basics/SharedWeakCachePointer.h>
 
@@ -164,4 +163,3 @@ SharedWeakCachePointer<T>::convertToWeak()
     return false;
 }
 }  // namespace xrpl
-#endif
diff --git a/include/xrpl/basics/SlabAllocator.h b/include/xrpl/basics/SlabAllocator.h
index 199eaf3bcc..2578afdc5a 100644
--- a/include/xrpl/basics/SlabAllocator.h
+++ b/include/xrpl/basics/SlabAllocator.h
@@ -1,7 +1,6 @@
 // Copyright (c) 2022, Nikolaos D. Bougalis <nikb@bougalis.net>
 
-#ifndef XRPL_BASICS_SLABALLOCATOR_H_INCLUDED
-#define XRPL_BASICS_SLABALLOCATOR_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/ByteUtilities.h>
 #include <xrpl/beast/type_name.h>
@@ -386,5 +385,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif  // XRPL_BASICS_SLABALLOCATOR_H_INCLUDED
diff --git a/include/xrpl/basics/Slice.h b/include/xrpl/basics/Slice.h
index b8990cb1bb..2f6081760f 100644
--- a/include/xrpl/basics/Slice.h
+++ b/include/xrpl/basics/Slice.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_SLICE_H_INCLUDED
-#define XRPL_BASICS_SLICE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/contract.h>
 #include <xrpl/basics/strHex.h>
@@ -231,5 +230,3 @@ makeSlice(std::basic_string<char, Traits, Alloc> const& s)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/StringUtilities.h b/include/xrpl/basics/StringUtilities.h
index 3d5a18f120..9b1cf4892d 100644
--- a/include/xrpl/basics/StringUtilities.h
+++ b/include/xrpl/basics/StringUtilities.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_STRINGUTILITIES_H_INCLUDED
-#define XRPL_BASICS_STRINGUTILITIES_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Blob.h>
 #include <xrpl/basics/strHex.h>
@@ -132,5 +131,3 @@ bool
 isProperlyFormedTomlDomain(std::string_view domain);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/TaggedCache.h b/include/xrpl/basics/TaggedCache.h
index 66547ea124..ef4c32903e 100644
--- a/include/xrpl/basics/TaggedCache.h
+++ b/include/xrpl/basics/TaggedCache.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_TAGGEDCACHE_H_INCLUDED
-#define XRPL_BASICS_TAGGEDCACHE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/IntrusivePointer.h>
 #include <xrpl/basics/Log.h>
@@ -295,5 +294,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/TaggedCache.ipp b/include/xrpl/basics/TaggedCache.ipp
index 15484ca817..c2f0999d5f 100644
--- a/include/xrpl/basics/TaggedCache.ipp
+++ b/include/xrpl/basics/TaggedCache.ipp
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_TAGGEDCACHE_IPP_INCLUDED
-#define XRPL_BASICS_TAGGEDCACHE_IPP_INCLUDED
+#pragma once
 
 #include <xrpl/basics/IntrusivePointer.ipp>
 #include <xrpl/basics/TaggedCache.h>
@@ -768,5 +767,3 @@ TaggedCache<Key, T, IsKeyCache, SharedWeakUnionPointer, SharedPointerType, Hash,
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/ToString.h b/include/xrpl/basics/ToString.h
index fe3a6a0893..a6254a1880 100644
--- a/include/xrpl/basics/ToString.h
+++ b/include/xrpl/basics/ToString.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_TOSTRING_H_INCLUDED
-#define XRPL_BASICS_TOSTRING_H_INCLUDED
+#pragma once
 
 #include <string>
 #include <type_traits>
@@ -44,5 +43,3 @@ to_string(char const* s)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/UnorderedContainers.h b/include/xrpl/basics/UnorderedContainers.h
index 75d1fdb8da..c614f9ea80 100644
--- a/include/xrpl/basics/UnorderedContainers.h
+++ b/include/xrpl/basics/UnorderedContainers.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_UNORDEREDCONTAINERS_H_INCLUDED
-#define XRPL_BASICS_UNORDEREDCONTAINERS_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/hardened_hash.h>
 #include <xrpl/basics/partitioned_unordered_map.h>
@@ -99,5 +98,3 @@ template <
 using hardened_hash_multiset = std::unordered_multiset<Value, Hash, Pred, Allocator>;
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/UptimeClock.h b/include/xrpl/basics/UptimeClock.h
index 9e1ef10d19..4edd38d274 100644
--- a/include/xrpl/basics/UptimeClock.h
+++ b/include/xrpl/basics/UptimeClock.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_UPTIMETIMER_H_INCLUDED
-#define XRPL_BASICS_UPTIMETIMER_H_INCLUDED
+#pragma once
 
 #include <atomic>
 #include <chrono>
@@ -46,5 +45,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/algorithm.h b/include/xrpl/basics/algorithm.h
index 1f536764db..2378c695df 100644
--- a/include/xrpl/basics/algorithm.h
+++ b/include/xrpl/basics/algorithm.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_ALGORITHM_H_INCLUDED
-#define XRPL_ALGORITHM_H_INCLUDED
+#pragma once
 
 #include <utility>
 
@@ -90,5 +89,3 @@ remove_if_intersect_or_match(FwdIter1 first1, FwdIter1 last1, InputIter2 first2,
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/base64.h b/include/xrpl/basics/base64.h
index 508196cf11..1725ee42f6 100644
--- a/include/xrpl/basics/base64.h
+++ b/include/xrpl/basics/base64.h
@@ -32,8 +32,7 @@
 
 */
 
-#ifndef XRPL_BASICS_BASE64_H_INCLUDED
-#define XRPL_BASICS_BASE64_H_INCLUDED
+#pragma once
 
 #include <cstdint>
 #include <string>
@@ -53,5 +52,3 @@ std::string
 base64_decode(std::string_view data);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/base_uint.h b/include/xrpl/basics/base_uint.h
index 32d6ad20fc..745cb7ab40 100644
--- a/include/xrpl/basics/base_uint.h
+++ b/include/xrpl/basics/base_uint.h
@@ -3,8 +3,7 @@
 // Distributed under the MIT/X11 software license, see the accompanying
 // file license.txt or http://www.opensource.org/licenses/mit-license.php.
 
-#ifndef XRPL_BASICS_BASE_UINT_H_INCLUDED
-#define XRPL_BASICS_BASE_UINT_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Expected.h>
 #include <xrpl/basics/Slice.h>
@@ -644,5 +643,3 @@ struct is_uniquely_represented<xrpl::base_uint<Bits, Tag>> : public std::true_ty
 };
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/basics/chrono.h b/include/xrpl/basics/chrono.h
index b542d1ded2..bcf988b45e 100644
--- a/include/xrpl/basics/chrono.h
+++ b/include/xrpl/basics/chrono.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_CHRONO_H_INCLUDED
-#define XRPL_BASICS_CHRONO_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/clock/abstract_clock.h>
 #include <xrpl/beast/clock/basic_seconds_clock.h>
@@ -99,5 +98,3 @@ stopwatch()
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/comparators.h b/include/xrpl/basics/comparators.h
index 7c848f0b3b..0e21d38d6b 100644
--- a/include/xrpl/basics/comparators.h
+++ b/include/xrpl/basics/comparators.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_COMPARATORS_H_INCLUDED
-#define XRPL_BASICS_COMPARATORS_H_INCLUDED
+#pragma once
 
 #include <functional>
 
@@ -53,5 +52,3 @@ using equal_to = std::equal_to<T>;
 #endif
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/contract.h b/include/xrpl/basics/contract.h
index bd2025dd17..8be257bb02 100644
--- a/include/xrpl/basics/contract.h
+++ b/include/xrpl/basics/contract.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_CONTRACT_H_INCLUDED
-#define XRPL_BASICS_CONTRACT_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/type_name.h>
 
@@ -48,5 +47,3 @@ Throw(Args&&... args)
 LogicError(std::string const& how) noexcept;
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/hardened_hash.h b/include/xrpl/basics/hardened_hash.h
index a25dcb3c34..b05ecda7a6 100644
--- a/include/xrpl/basics/hardened_hash.h
+++ b/include/xrpl/basics/hardened_hash.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_HARDENED_HASH_H_INCLUDED
-#define XRPL_BASICS_HARDENED_HASH_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/hash/hash_append.h>
 #include <xrpl/beast/hash/xxhasher.h>
@@ -93,5 +92,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/join.h b/include/xrpl/basics/join.h
index 890b6fdc10..16fae4ff87 100644
--- a/include/xrpl/basics/join.h
+++ b/include/xrpl/basics/join.h
@@ -1,5 +1,4 @@
-#ifndef JOIN_H_INCLUDED
-#define JOIN_H_INCLUDED
+#pragma once
 
 #include <string>
 
@@ -80,5 +79,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/make_SSLContext.h b/include/xrpl/basics/make_SSLContext.h
index fb91dd40a9..1714d3e58c 100644
--- a/include/xrpl/basics/make_SSLContext.h
+++ b/include/xrpl/basics/make_SSLContext.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_MAKE_SSLCONTEXT_H_INCLUDED
-#define XRPL_BASICS_MAKE_SSLCONTEXT_H_INCLUDED
+#pragma once
 
 #include <boost/asio/ssl/context.hpp>
 
@@ -20,5 +19,3 @@ make_SSLContextAuthed(
     std::string const& cipherList);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/mulDiv.h b/include/xrpl/basics/mulDiv.h
index fb38d0cd63..2495f07728 100644
--- a/include/xrpl/basics/mulDiv.h
+++ b/include/xrpl/basics/mulDiv.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_MULDIV_H_INCLUDED
-#define XRPL_BASICS_MULDIV_H_INCLUDED
+#pragma once
 
 #include <cstdint>
 #include <limits>
@@ -22,5 +21,3 @@ std::optional<std::uint64_t>
 mulDiv(std::uint64_t value, std::uint64_t mul, std::uint64_t div);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/partitioned_unordered_map.h b/include/xrpl/basics/partitioned_unordered_map.h
index f011fb9508..181597ca69 100644
--- a/include/xrpl/basics/partitioned_unordered_map.h
+++ b/include/xrpl/basics/partitioned_unordered_map.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_PARTITIONED_UNORDERED_MAP_H
-#define XRPL_BASICS_PARTITIONED_UNORDERED_MAP_H
+#pragma once
 
 #include <xrpl/beast/hash/uhash.h>
 #include <xrpl/beast/utility/instrumentation.h>
@@ -393,5 +392,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif  // XRPL_BASICS_PARTITIONED_UNORDERED_MAP_H
diff --git a/include/xrpl/basics/random.h b/include/xrpl/basics/random.h
index 74ec14c742..34e460fd8a 100644
--- a/include/xrpl/basics/random.h
+++ b/include/xrpl/basics/random.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_RANDOM_H_INCLUDED
-#define XRPL_BASICS_RANDOM_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/beast/xor_shift_engine.h>
@@ -174,5 +173,3 @@ rand_bool()
 /** @} */
 
 }  // namespace xrpl
-
-#endif  // XRPL_BASICS_RANDOM_H_INCLUDED
diff --git a/include/xrpl/basics/rocksdb.h b/include/xrpl/basics/rocksdb.h
index 59a69a9b44..3d468b0f1b 100644
--- a/include/xrpl/basics/rocksdb.h
+++ b/include/xrpl/basics/rocksdb.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_ROCKSDB_H_INCLUDED
-#define XRPL_BASICS_ROCKSDB_H_INCLUDED
+#pragma once
 
 #if XRPL_ROCKSDB_AVAILABLE
 // #include <rocksdb2/port/port_posix.h>
@@ -28,5 +27,3 @@
 #include <rocksdb/write_batch.h>
 
 #endif
-
-#endif
diff --git a/include/xrpl/basics/safe_cast.h b/include/xrpl/basics/safe_cast.h
index 903f916194..285d76782a 100644
--- a/include/xrpl/basics/safe_cast.h
+++ b/include/xrpl/basics/safe_cast.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_SAFE_CAST_H_INCLUDED
-#define XRPL_BASICS_SAFE_CAST_H_INCLUDED
+#pragma once
 
 #include <type_traits>
 
@@ -69,5 +68,3 @@ unsafe_cast(Src s) noexcept
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/scope.h b/include/xrpl/basics/scope.h
index f0643c420c..797a7d3fdc 100644
--- a/include/xrpl/basics/scope.h
+++ b/include/xrpl/basics/scope.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_SCOPE_H_INCLUDED
-#define XRPL_BASICS_SCOPE_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/instrumentation.h>
 
@@ -220,5 +219,3 @@ template <class Mutex>
 scope_unlock(std::unique_lock<Mutex>&) -> scope_unlock<Mutex>;
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/spinlock.h b/include/xrpl/basics/spinlock.h
index f612aaf548..7b05b7c339 100644
--- a/include/xrpl/basics/spinlock.h
+++ b/include/xrpl/basics/spinlock.h
@@ -1,7 +1,6 @@
 // Copyright (c) 2022, Nikolaos D. Bougalis <nikb@bougalis.net>
 
-#ifndef XRPL_BASICS_SPINLOCK_H_INCLUDED
-#define XRPL_BASICS_SPINLOCK_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/instrumentation.h>
 
@@ -201,5 +200,3 @@ public:
 /** @} */
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/strHex.h b/include/xrpl/basics/strHex.h
index 38b9a15668..76a3d86ff3 100644
--- a/include/xrpl/basics/strHex.h
+++ b/include/xrpl/basics/strHex.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_STRHEX_H_INCLUDED
-#define XRPL_BASICS_STRHEX_H_INCLUDED
+#pragma once
 
 #include <boost/algorithm/hex.hpp>
 #include <boost/endian/conversion.hpp>
@@ -27,5 +26,3 @@ strHex(T const& from)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/basics/tagged_integer.h b/include/xrpl/basics/tagged_integer.h
index a44daf1342..439cc537e2 100644
--- a/include/xrpl/basics/tagged_integer.h
+++ b/include/xrpl/basics/tagged_integer.h
@@ -1,7 +1,6 @@
 // Copyright (c) 2014, Nikolaos D. Bougalis <nikb@bougalis.net>
 
-#ifndef BEAST_UTILITY_TAGGED_INTEGER_H_INCLUDED
-#define BEAST_UTILITY_TAGGED_INTEGER_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/hash/hash_append.h>
 
@@ -202,4 +201,3 @@ struct is_contiguously_hashable<xrpl::tagged_integer<Int, Tag>, HashAlgorithm>
 };
 
 }  // namespace beast
-#endif
diff --git a/include/xrpl/beast/asio/io_latency_probe.h b/include/xrpl/beast/asio/io_latency_probe.h
index 8ee4fdb89a..347203acb3 100644
--- a/include/xrpl/beast/asio/io_latency_probe.h
+++ b/include/xrpl/beast/asio/io_latency_probe.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_ASIO_IO_LATENCY_PROBE_H_INCLUDED
-#define BEAST_ASIO_IO_LATENCY_PROBE_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/instrumentation.h>
 
@@ -226,5 +225,3 @@ private:
 };
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/clock/abstract_clock.h b/include/xrpl/beast/clock/abstract_clock.h
index 6f71529fda..41b57fdd2c 100644
--- a/include/xrpl/beast/clock/abstract_clock.h
+++ b/include/xrpl/beast/clock/abstract_clock.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_CHRONO_ABSTRACT_CLOCK_H_INCLUDED
-#define BEAST_CHRONO_ABSTRACT_CLOCK_H_INCLUDED
+#pragma once
 
 namespace beast {
 
@@ -89,5 +88,3 @@ get_abstract_clock()
 }
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/clock/basic_seconds_clock.h b/include/xrpl/beast/clock/basic_seconds_clock.h
index 65dbe5abc7..5205d92fef 100644
--- a/include/xrpl/beast/clock/basic_seconds_clock.h
+++ b/include/xrpl/beast/clock/basic_seconds_clock.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_CHRONO_BASIC_SECONDS_CLOCK_H_INCLUDED
-#define BEAST_CHRONO_BASIC_SECONDS_CLOCK_H_INCLUDED
+#pragma once
 
 #include <chrono>
 
@@ -33,5 +32,3 @@ public:
 };
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/clock/manual_clock.h b/include/xrpl/beast/clock/manual_clock.h
index 975656cf63..a301b4e1fe 100644
--- a/include/xrpl/beast/clock/manual_clock.h
+++ b/include/xrpl/beast/clock/manual_clock.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_CHRONO_MANUAL_CLOCK_H_INCLUDED
-#define BEAST_CHRONO_MANUAL_CLOCK_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/clock/abstract_clock.h>
 #include <xrpl/beast/utility/instrumentation.h>
@@ -75,5 +74,3 @@ public:
 };
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/container/aged_container.h b/include/xrpl/beast/container/aged_container.h
index 6051db7f69..dd622fcd9a 100644
--- a/include/xrpl/beast/container/aged_container.h
+++ b/include/xrpl/beast/container/aged_container.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_CONTAINER_AGED_CONTAINER_H_INCLUDED
-#define BEAST_CONTAINER_AGED_CONTAINER_H_INCLUDED
+#pragma once
 
 #include <type_traits>
 
@@ -12,5 +11,3 @@ struct is_aged_container : std::false_type
 };
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/container/aged_container_utility.h b/include/xrpl/beast/container/aged_container_utility.h
index 8847fcb321..fd5d481aa5 100644
--- a/include/xrpl/beast/container/aged_container_utility.h
+++ b/include/xrpl/beast/container/aged_container_utility.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_CONTAINER_AGED_CONTAINER_UTILITY_H_INCLUDED
-#define BEAST_CONTAINER_AGED_CONTAINER_UTILITY_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/container/aged_container.h>
 
@@ -24,5 +23,3 @@ expire(AgedContainer& c, std::chrono::duration<Rep, Period> const& age)
 }
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/container/aged_map.h b/include/xrpl/beast/container/aged_map.h
index f3bc59943d..e9505f2763 100644
--- a/include/xrpl/beast/container/aged_map.h
+++ b/include/xrpl/beast/container/aged_map.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_CONTAINER_AGED_MAP_H_INCLUDED
-#define BEAST_CONTAINER_AGED_MAP_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/container/detail/aged_ordered_container.h>
 
@@ -18,5 +17,3 @@ template <
 using aged_map = detail::aged_ordered_container<false, true, Key, T, Clock, Compare, Allocator>;
 
 }
-
-#endif
diff --git a/include/xrpl/beast/container/aged_multimap.h b/include/xrpl/beast/container/aged_multimap.h
index 3602996602..7625694f66 100644
--- a/include/xrpl/beast/container/aged_multimap.h
+++ b/include/xrpl/beast/container/aged_multimap.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_CONTAINER_AGED_MULTIMAP_H_INCLUDED
-#define BEAST_CONTAINER_AGED_MULTIMAP_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/container/detail/aged_ordered_container.h>
 
@@ -18,5 +17,3 @@ template <
 using aged_multimap = detail::aged_ordered_container<true, true, Key, T, Clock, Compare, Allocator>;
 
 }
-
-#endif
diff --git a/include/xrpl/beast/container/aged_multiset.h b/include/xrpl/beast/container/aged_multiset.h
index 851dd8fa6e..2ad09344e5 100644
--- a/include/xrpl/beast/container/aged_multiset.h
+++ b/include/xrpl/beast/container/aged_multiset.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_CONTAINER_AGED_MULTISET_H_INCLUDED
-#define BEAST_CONTAINER_AGED_MULTISET_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/container/detail/aged_ordered_container.h>
 
@@ -17,5 +16,3 @@ template <
 using aged_multiset = detail::aged_ordered_container<true, false, Key, void, Clock, Compare, Allocator>;
 
 }
-
-#endif
diff --git a/include/xrpl/beast/container/aged_set.h b/include/xrpl/beast/container/aged_set.h
index 99b2c58bf6..2c601f5f41 100644
--- a/include/xrpl/beast/container/aged_set.h
+++ b/include/xrpl/beast/container/aged_set.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_CONTAINER_AGED_SET_H_INCLUDED
-#define BEAST_CONTAINER_AGED_SET_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/container/detail/aged_ordered_container.h>
 
@@ -17,5 +16,3 @@ template <
 using aged_set = detail::aged_ordered_container<false, false, Key, void, Clock, Compare, Allocator>;
 
 }
-
-#endif
diff --git a/include/xrpl/beast/container/aged_unordered_map.h b/include/xrpl/beast/container/aged_unordered_map.h
index 26e41534d3..116d5669a1 100644
--- a/include/xrpl/beast/container/aged_unordered_map.h
+++ b/include/xrpl/beast/container/aged_unordered_map.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_CONTAINER_AGED_UNORDERED_MAP_H_INCLUDED
-#define BEAST_CONTAINER_AGED_UNORDERED_MAP_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/container/detail/aged_unordered_container.h>
 
@@ -19,5 +18,3 @@ template <
 using aged_unordered_map = detail::aged_unordered_container<false, true, Key, T, Clock, Hash, KeyEqual, Allocator>;
 
 }
-
-#endif
diff --git a/include/xrpl/beast/container/aged_unordered_multimap.h b/include/xrpl/beast/container/aged_unordered_multimap.h
index 3202aef27d..4c3333a099 100644
--- a/include/xrpl/beast/container/aged_unordered_multimap.h
+++ b/include/xrpl/beast/container/aged_unordered_multimap.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_CONTAINER_AGED_UNORDERED_MULTIMAP_H_INCLUDED
-#define BEAST_CONTAINER_AGED_UNORDERED_MULTIMAP_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/container/detail/aged_unordered_container.h>
 
@@ -19,5 +18,3 @@ template <
 using aged_unordered_multimap = detail::aged_unordered_container<true, true, Key, T, Clock, Hash, KeyEqual, Allocator>;
 
 }
-
-#endif
diff --git a/include/xrpl/beast/container/aged_unordered_multiset.h b/include/xrpl/beast/container/aged_unordered_multiset.h
index b42cad6a2f..b251f20077 100644
--- a/include/xrpl/beast/container/aged_unordered_multiset.h
+++ b/include/xrpl/beast/container/aged_unordered_multiset.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_CONTAINER_AGED_UNORDERED_MULTISET_H_INCLUDED
-#define BEAST_CONTAINER_AGED_UNORDERED_MULTISET_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/container/detail/aged_unordered_container.h>
 
@@ -19,5 +18,3 @@ using aged_unordered_multiset =
     detail::aged_unordered_container<true, false, Key, void, Clock, Hash, KeyEqual, Allocator>;
 
 }
-
-#endif
diff --git a/include/xrpl/beast/container/aged_unordered_set.h b/include/xrpl/beast/container/aged_unordered_set.h
index d095408849..a8ee61f1f5 100644
--- a/include/xrpl/beast/container/aged_unordered_set.h
+++ b/include/xrpl/beast/container/aged_unordered_set.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_CONTAINER_AGED_UNORDERED_SET_H_INCLUDED
-#define BEAST_CONTAINER_AGED_UNORDERED_SET_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/container/detail/aged_unordered_container.h>
 
@@ -18,5 +17,3 @@ template <
 using aged_unordered_set = detail::aged_unordered_container<false, false, Key, void, Clock, Hash, KeyEqual, Allocator>;
 
 }
-
-#endif
diff --git a/include/xrpl/beast/container/detail/aged_associative_container.h b/include/xrpl/beast/container/detail/aged_associative_container.h
index ab08484aa3..34e9560cbb 100644
--- a/include/xrpl/beast/container/detail/aged_associative_container.h
+++ b/include/xrpl/beast/container/detail/aged_associative_container.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_CONTAINER_DETAIL_AGED_ASSOCIATIVE_CONTAINER_H_INCLUDED
-#define BEAST_CONTAINER_DETAIL_AGED_ASSOCIATIVE_CONTAINER_H_INCLUDED
+#pragma once
 
 namespace beast {
 namespace detail {
@@ -33,5 +32,3 @@ struct aged_associative_container_extract_t<false>
 
 }  // namespace detail
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/container/detail/aged_container_iterator.h b/include/xrpl/beast/container/detail/aged_container_iterator.h
index 5cee583d74..12cd15f677 100644
--- a/include/xrpl/beast/container/detail/aged_container_iterator.h
+++ b/include/xrpl/beast/container/detail/aged_container_iterator.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_CONTAINER_DETAIL_AGED_CONTAINER_ITERATOR_H_INCLUDED
-#define BEAST_CONTAINER_DETAIL_AGED_CONTAINER_ITERATOR_H_INCLUDED
+#pragma once
 
 #include <iterator>
 #include <type_traits>
@@ -146,5 +145,3 @@ private:
 }  // namespace detail
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/container/detail/aged_ordered_container.h b/include/xrpl/beast/container/detail/aged_ordered_container.h
index d4ba81f0b8..2f3d8973e9 100644
--- a/include/xrpl/beast/container/detail/aged_ordered_container.h
+++ b/include/xrpl/beast/container/detail/aged_ordered_container.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_CONTAINER_DETAIL_AGED_ORDERED_CONTAINER_H_INCLUDED
-#define BEAST_CONTAINER_DETAIL_AGED_ORDERED_CONTAINER_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/clock/abstract_clock.h>
 #include <xrpl/beast/container/aged_container.h>
@@ -1687,5 +1686,3 @@ expire(
 }
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/container/detail/aged_unordered_container.h b/include/xrpl/beast/container/detail/aged_unordered_container.h
index 96dd196f32..a73ec107a7 100644
--- a/include/xrpl/beast/container/detail/aged_unordered_container.h
+++ b/include/xrpl/beast/container/detail/aged_unordered_container.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_CONTAINER_DETAIL_AGED_UNORDERED_CONTAINER_H_INCLUDED
-#define BEAST_CONTAINER_DETAIL_AGED_UNORDERED_CONTAINER_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/clock/abstract_clock.h>
 #include <xrpl/beast/container/aged_container.h>
@@ -2226,5 +2225,3 @@ expire(
 }
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/container/detail/empty_base_optimization.h b/include/xrpl/beast/container/detail/empty_base_optimization.h
index 9f3a2ffdf2..21a9d13ce8 100644
--- a/include/xrpl/beast/container/detail/empty_base_optimization.h
+++ b/include/xrpl/beast/container/detail/empty_base_optimization.h
@@ -4,8 +4,7 @@
 // Official repository: https://github.com/boostorg/beast
 //
 
-#ifndef BEAST_CONTAINER_DETAIL_EMPTY_BASE_OPTIMIZATION_H_INCLUDED
-#define BEAST_CONTAINER_DETAIL_EMPTY_BASE_OPTIMIZATION_H_INCLUDED
+#pragma once
 
 #include <boost/type_traits/is_final.hpp>
 
@@ -89,5 +88,3 @@ public:
 
 }  // namespace detail
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/core/CurrentThreadName.h b/include/xrpl/beast/core/CurrentThreadName.h
index 87fa042f81..8e99ee90da 100644
--- a/include/xrpl/beast/core/CurrentThreadName.h
+++ b/include/xrpl/beast/core/CurrentThreadName.h
@@ -2,8 +2,7 @@
 // Copyright (c) 2013 - Raw Material Software Ltd.
 // Please visit http://www.juce.com
 
-#ifndef BEAST_CORE_CURRENT_THREAD_NAME_H_INCLUDED
-#define BEAST_CORE_CURRENT_THREAD_NAME_H_INCLUDED
+#pragma once
 
 #include <boost/predef.h>
 
@@ -53,5 +52,3 @@ std::string
 getCurrentThreadName();
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/core/LexicalCast.h b/include/xrpl/beast/core/LexicalCast.h
index b0322614b5..a7c135f23f 100644
--- a/include/xrpl/beast/core/LexicalCast.h
+++ b/include/xrpl/beast/core/LexicalCast.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_MODULE_CORE_TEXT_LEXICALCAST_H_INCLUDED
-#define BEAST_MODULE_CORE_TEXT_LEXICALCAST_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/instrumentation.h>
 
@@ -208,5 +207,3 @@ lexicalCast(In in, Out defaultValue = Out())
 }
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/core/List.h b/include/xrpl/beast/core/List.h
index edd1b4530f..75c981ea1b 100644
--- a/include/xrpl/beast/core/List.h
+++ b/include/xrpl/beast/core/List.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_INTRUSIVE_LIST_H_INCLUDED
-#define BEAST_INTRUSIVE_LIST_H_INCLUDED
+#pragma once
 
 #include <iterator>
 
@@ -574,5 +573,3 @@ private:
 };
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/core/LockFreeStack.h b/include/xrpl/beast/core/LockFreeStack.h
index 7e358dccbd..bb32698dd8 100644
--- a/include/xrpl/beast/core/LockFreeStack.h
+++ b/include/xrpl/beast/core/LockFreeStack.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_INTRUSIVE_LOCKFREESTACK_H_INCLUDED
-#define BEAST_INTRUSIVE_LOCKFREESTACK_H_INCLUDED
+#pragma once
 
 #include <atomic>
 #include <iterator>
@@ -268,5 +267,3 @@ private:
 };
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/core/SemanticVersion.h b/include/xrpl/beast/core/SemanticVersion.h
index fabda8290f..1d3525de25 100644
--- a/include/xrpl/beast/core/SemanticVersion.h
+++ b/include/xrpl/beast/core/SemanticVersion.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_MODULE_CORE_DIAGNOSTIC_SEMANTICVERSION_H_INCLUDED
-#define BEAST_MODULE_CORE_DIAGNOSTIC_SEMANTICVERSION_H_INCLUDED
+#pragma once
 
 #include <string>
 #include <vector>
@@ -95,5 +94,3 @@ operator<(SemanticVersion const& lhs, SemanticVersion const& rhs)
 }
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/hash/hash_append.h b/include/xrpl/beast/hash/hash_append.h
index f69931cb96..e4d646e532 100644
--- a/include/xrpl/beast/hash/hash_append.h
+++ b/include/xrpl/beast/hash/hash_append.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_HASH_HASH_APPEND_H_INCLUDED
-#define BEAST_HASH_HASH_APPEND_H_INCLUDED
+#pragma once
 
 #include <boost/container/flat_set.hpp>
 #include <boost/endian/conversion.hpp>
@@ -440,5 +439,3 @@ hash_append(HashAlgorithm& h, std::error_code const& ec)
 }
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/hash/uhash.h b/include/xrpl/beast/hash/uhash.h
index c167412e3a..4f66f058a8 100644
--- a/include/xrpl/beast/hash/uhash.h
+++ b/include/xrpl/beast/hash/uhash.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_HASH_UHASH_H_INCLUDED
-#define BEAST_HASH_UHASH_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/hash/hash_append.h>
 #include <xrpl/beast/hash/xxhasher.h>
@@ -25,5 +24,3 @@ struct uhash
 };
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/hash/xxhasher.h b/include/xrpl/beast/hash/xxhasher.h
index 098551f02e..473907ea89 100644
--- a/include/xrpl/beast/hash/xxhasher.h
+++ b/include/xrpl/beast/hash/xxhasher.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_HASH_XXHASHER_H_INCLUDED
-#define BEAST_HASH_XXHASHER_H_INCLUDED
+#pragma once
 
 #include <boost/endian/conversion.hpp>
 
@@ -152,5 +151,3 @@ public:
 };
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/insight/Collector.h b/include/xrpl/beast/insight/Collector.h
index 045d9003a9..89aa8c1cb5 100644
--- a/include/xrpl/beast/insight/Collector.h
+++ b/include/xrpl/beast/insight/Collector.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_INSIGHT_COLLECTOR_H_INCLUDED
-#define BEAST_INSIGHT_COLLECTOR_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/insight/Counter.h>
 #include <xrpl/beast/insight/Event.h>
@@ -120,5 +119,3 @@ public:
 
 }  // namespace insight
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/insight/Counter.h b/include/xrpl/beast/insight/Counter.h
index e1b8c36545..f6722c4e03 100644
--- a/include/xrpl/beast/insight/Counter.h
+++ b/include/xrpl/beast/insight/Counter.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_INSIGHT_COUNTER_H_INCLUDED
-#define BEAST_INSIGHT_COUNTER_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/insight/CounterImpl.h>
 
@@ -94,5 +93,3 @@ private:
 
 }  // namespace insight
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/insight/CounterImpl.h b/include/xrpl/beast/insight/CounterImpl.h
index 409cfe07a7..199315dcb8 100644
--- a/include/xrpl/beast/insight/CounterImpl.h
+++ b/include/xrpl/beast/insight/CounterImpl.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_INSIGHT_COUNTERIMPL_H_INCLUDED
-#define BEAST_INSIGHT_COUNTERIMPL_H_INCLUDED
+#pragma once
 
 #include <cstdint>
 #include <memory>
@@ -21,5 +20,3 @@ public:
 
 }  // namespace insight
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/insight/Event.h b/include/xrpl/beast/insight/Event.h
index c375c34f9c..bc0c0dd403 100644
--- a/include/xrpl/beast/insight/Event.h
+++ b/include/xrpl/beast/insight/Event.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_INSIGHT_EVENT_H_INCLUDED
-#define BEAST_INSIGHT_EVENT_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/insight/EventImpl.h>
 
@@ -61,5 +60,3 @@ private:
 
 }  // namespace insight
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/insight/EventImpl.h b/include/xrpl/beast/insight/EventImpl.h
index cec378e71e..abd9741511 100644
--- a/include/xrpl/beast/insight/EventImpl.h
+++ b/include/xrpl/beast/insight/EventImpl.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_INSIGHT_EVENTIMPL_H_INCLUDED
-#define BEAST_INSIGHT_EVENTIMPL_H_INCLUDED
+#pragma once
 
 #include <chrono>
 #include <memory>
@@ -21,5 +20,3 @@ public:
 
 }  // namespace insight
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/insight/Gauge.h b/include/xrpl/beast/insight/Gauge.h
index c9c1b64cda..f2a88deda2 100644
--- a/include/xrpl/beast/insight/Gauge.h
+++ b/include/xrpl/beast/insight/Gauge.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_INSIGHT_GAUGE_H_INCLUDED
-#define BEAST_INSIGHT_GAUGE_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/insight/GaugeImpl.h>
 
@@ -124,5 +123,3 @@ private:
 
 }  // namespace insight
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/insight/GaugeImpl.h b/include/xrpl/beast/insight/GaugeImpl.h
index c20d93744d..29afbe6a4d 100644
--- a/include/xrpl/beast/insight/GaugeImpl.h
+++ b/include/xrpl/beast/insight/GaugeImpl.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_INSIGHT_GAUGEIMPL_H_INCLUDED
-#define BEAST_INSIGHT_GAUGEIMPL_H_INCLUDED
+#pragma once
 
 #include <cstdint>
 #include <memory>
@@ -24,5 +23,3 @@ public:
 
 }  // namespace insight
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/insight/Group.h b/include/xrpl/beast/insight/Group.h
index 8119b4004f..c85fd1bfb6 100644
--- a/include/xrpl/beast/insight/Group.h
+++ b/include/xrpl/beast/insight/Group.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_INSIGHT_GROUP_H_INCLUDED
-#define BEAST_INSIGHT_GROUP_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/insight/Collector.h>
 
@@ -22,5 +21,3 @@ public:
 
 }  // namespace insight
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/insight/Groups.h b/include/xrpl/beast/insight/Groups.h
index 2fc996fcf8..8ac93454d3 100644
--- a/include/xrpl/beast/insight/Groups.h
+++ b/include/xrpl/beast/insight/Groups.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_INSIGHT_GROUPS_H_INCLUDED
-#define BEAST_INSIGHT_GROUPS_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/insight/Collector.h>
 #include <xrpl/beast/insight/Group.h>
@@ -35,5 +34,3 @@ make_Groups(Collector::ptr const& collector);
 
 }  // namespace insight
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/insight/Hook.h b/include/xrpl/beast/insight/Hook.h
index 1dc4cd0c74..ea511862d9 100644
--- a/include/xrpl/beast/insight/Hook.h
+++ b/include/xrpl/beast/insight/Hook.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_INSIGHT_HOOK_H_INCLUDED
-#define BEAST_INSIGHT_HOOK_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/insight/HookImpl.h>
 
@@ -40,5 +39,3 @@ private:
 
 }  // namespace insight
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/insight/HookImpl.h b/include/xrpl/beast/insight/HookImpl.h
index dadbc6d106..18208b554a 100644
--- a/include/xrpl/beast/insight/HookImpl.h
+++ b/include/xrpl/beast/insight/HookImpl.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_INSIGHT_HOOKIMPL_H_INCLUDED
-#define BEAST_INSIGHT_HOOKIMPL_H_INCLUDED
+#pragma once
 
 #include <functional>
 #include <memory>
@@ -17,5 +16,3 @@ public:
 
 }  // namespace insight
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/insight/Insight.h b/include/xrpl/beast/insight/Insight.h
index c298510291..bf3743cfd8 100644
--- a/include/xrpl/beast/insight/Insight.h
+++ b/include/xrpl/beast/insight/Insight.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_INSIGHT_H_INCLUDED
-#define BEAST_INSIGHT_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/insight/Collector.h>
 #include <xrpl/beast/insight/Counter.h>
@@ -14,5 +13,3 @@
 #include <xrpl/beast/insight/HookImpl.h>
 #include <xrpl/beast/insight/NullCollector.h>
 #include <xrpl/beast/insight/StatsDCollector.h>
-
-#endif
diff --git a/include/xrpl/beast/insight/Meter.h b/include/xrpl/beast/insight/Meter.h
index 34aa4c59d4..193a1f1003 100644
--- a/include/xrpl/beast/insight/Meter.h
+++ b/include/xrpl/beast/insight/Meter.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_INSIGHT_METER_H_INCLUDED
-#define BEAST_INSIGHT_METER_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/insight/MeterImpl.h>
 
@@ -79,5 +78,3 @@ private:
 
 }  // namespace insight
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/insight/MeterImpl.h b/include/xrpl/beast/insight/MeterImpl.h
index c50dc07295..22efdbe647 100644
--- a/include/xrpl/beast/insight/MeterImpl.h
+++ b/include/xrpl/beast/insight/MeterImpl.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_INSIGHT_METERIMPL_H_INCLUDED
-#define BEAST_INSIGHT_METERIMPL_H_INCLUDED
+#pragma once
 
 #include <cstdint>
 #include <memory>
@@ -21,5 +20,3 @@ public:
 
 }  // namespace insight
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/insight/NullCollector.h b/include/xrpl/beast/insight/NullCollector.h
index 6c4413007b..1d16a11e17 100644
--- a/include/xrpl/beast/insight/NullCollector.h
+++ b/include/xrpl/beast/insight/NullCollector.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_INSIGHT_NULLCOLLECTOR_H_INCLUDED
-#define BEAST_INSIGHT_NULLCOLLECTOR_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/insight/Collector.h>
 
@@ -18,5 +17,3 @@ public:
 
 }  // namespace insight
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/insight/StatsDCollector.h b/include/xrpl/beast/insight/StatsDCollector.h
index 9c63ab4ed9..ab09967483 100644
--- a/include/xrpl/beast/insight/StatsDCollector.h
+++ b/include/xrpl/beast/insight/StatsDCollector.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_INSIGHT_STATSDCOLLECTOR_H_INCLUDED
-#define BEAST_INSIGHT_STATSDCOLLECTOR_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/insight/Collector.h>
 #include <xrpl/beast/net/IPEndpoint.h>
@@ -28,5 +27,3 @@ public:
 
 }  // namespace insight
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/net/IPAddress.h b/include/xrpl/beast/net/IPAddress.h
index c3c7ee3d56..2ac4c3bc43 100644
--- a/include/xrpl/beast/net/IPAddress.h
+++ b/include/xrpl/beast/net/IPAddress.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_NET_IPADDRESS_H_INCLUDED
-#define BEAST_NET_IPADDRESS_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/hash/hash_append.h>
 #include <xrpl/beast/hash/uhash.h>
@@ -96,5 +95,3 @@ struct hash<::beast::IP::Address>
     }
 };
 }  // namespace boost
-
-#endif
diff --git a/include/xrpl/beast/net/IPAddressConversion.h b/include/xrpl/beast/net/IPAddressConversion.h
index e05ae8541f..2ebd0a6eef 100644
--- a/include/xrpl/beast/net/IPAddressConversion.h
+++ b/include/xrpl/beast/net/IPAddressConversion.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_NET_IPADDRESSCONVERSION_H_INCLUDED
-#define BEAST_NET_IPADDRESSCONVERSION_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/net/IPEndpoint.h>
 
@@ -61,5 +60,3 @@ struct IPAddressConversion
 };
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/net/IPAddressV4.h b/include/xrpl/beast/net/IPAddressV4.h
index c654db85c0..0d586716d8 100644
--- a/include/xrpl/beast/net/IPAddressV4.h
+++ b/include/xrpl/beast/net/IPAddressV4.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_NET_IPADDRESSV4_H_INCLUDED
-#define BEAST_NET_IPADDRESSV4_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/hash/hash_append.h>
 
@@ -26,5 +25,3 @@ get_class(AddressV4 const& address);
 
 }  // namespace IP
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/net/IPAddressV6.h b/include/xrpl/beast/net/IPAddressV6.h
index a4f9c20f16..2f9dedb748 100644
--- a/include/xrpl/beast/net/IPAddressV6.h
+++ b/include/xrpl/beast/net/IPAddressV6.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_NET_IPADDRESSV6_H_INCLUDED
-#define BEAST_NET_IPADDRESSV6_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/instrumentation.h>
 
@@ -20,5 +19,3 @@ is_public(AddressV6 const& addr);
 
 }  // namespace IP
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/net/IPEndpoint.h b/include/xrpl/beast/net/IPEndpoint.h
index 3d09e7f8e6..7a0394cbd1 100644
--- a/include/xrpl/beast/net/IPEndpoint.h
+++ b/include/xrpl/beast/net/IPEndpoint.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_NET_IPENDPOINT_H_INCLUDED
-#define BEAST_NET_IPENDPOINT_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/hash/hash_append.h>
 #include <xrpl/beast/hash/uhash.h>
@@ -219,5 +218,3 @@ struct hash<::beast::IP::Endpoint>
     }
 };
 }  // namespace boost
-
-#endif
diff --git a/include/xrpl/beast/rfc2616.h b/include/xrpl/beast/rfc2616.h
index 922e4a7dc4..2ff770c011 100644
--- a/include/xrpl/beast/rfc2616.h
+++ b/include/xrpl/beast/rfc2616.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_RFC2616_HPP
-#define BEAST_RFC2616_HPP
+#pragma once
 
 #include <boost/beast/http/message.hpp>
 #include <boost/beast/http/rfc7230.hpp>
@@ -363,5 +362,3 @@ is_keep_alive(boost::beast::http::message<isRequest, Body, Fields> const& m)
 
 }  // namespace rfc2616
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/test/yield_to.h b/include/xrpl/beast/test/yield_to.h
index b20661bdca..b10530c0d3 100644
--- a/include/xrpl/beast/test/yield_to.h
+++ b/include/xrpl/beast/test/yield_to.h
@@ -2,8 +2,7 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#ifndef BEAST_TEST_YIELD_TO_HPP
-#define BEAST_TEST_YIELD_TO_HPP
+#pragma once
 
 #include <boost/asio/executor_work_guard.hpp>
 #include <boost/asio/io_context.hpp>
@@ -127,5 +126,3 @@ enable_yield_to::spawn(F0&& f, FN&&... fn)
 
 }  // namespace test
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/type_name.h b/include/xrpl/beast/type_name.h
index 1534af5eda..99b90d1757 100644
--- a/include/xrpl/beast/type_name.h
+++ b/include/xrpl/beast/type_name.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_TYPE_NAME_H_INCLUDED
-#define BEAST_TYPE_NAME_H_INCLUDED
+#pragma once
 
 #include <cstdlib>
 #include <string>
@@ -41,5 +40,3 @@ type_name()
 }
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/unit_test.h b/include/xrpl/beast/unit_test.h
index 721faef6f0..51ac96cacb 100644
--- a/include/xrpl/beast/unit_test.h
+++ b/include/xrpl/beast/unit_test.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_UNIT_TEST_H_INCLUDED
-#define BEAST_UNIT_TEST_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/unit_test/amount.h>
 #include <xrpl/beast/unit_test/global_suites.h>
@@ -19,5 +18,3 @@
 //__LINE__);}while(false){}
 #define BEAST_EXPECT(cond) expect(cond, __FILE__ ":" BEAST_EXPECT_S2(__LINE__))
 #endif
-
-#endif
diff --git a/include/xrpl/beast/unit_test/amount.h b/include/xrpl/beast/unit_test/amount.h
index 5082361fa6..aedced15a7 100644
--- a/include/xrpl/beast/unit_test/amount.h
+++ b/include/xrpl/beast/unit_test/amount.h
@@ -2,8 +2,7 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#ifndef BEAST_UNIT_TEST_AMOUNT_HPP
-#define BEAST_UNIT_TEST_AMOUNT_HPP
+#pragma once
 
 #include <cstddef>
 #include <ostream>
@@ -45,5 +44,3 @@ operator<<(std::ostream& s, amount const& t)
 
 }  // namespace unit_test
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/unit_test/detail/const_container.h b/include/xrpl/beast/unit_test/detail/const_container.h
index c1e8c03a27..7c52e0e1ec 100644
--- a/include/xrpl/beast/unit_test/detail/const_container.h
+++ b/include/xrpl/beast/unit_test/detail/const_container.h
@@ -2,8 +2,7 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#ifndef BEAST_UNIT_TEST_DETAIL_CONST_CONTAINER_HPP
-#define BEAST_UNIT_TEST_DETAIL_CONST_CONTAINER_HPP
+#pragma once
 
 namespace beast {
 namespace unit_test {
@@ -86,5 +85,3 @@ public:
 }  // namespace detail
 }  // namespace unit_test
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/unit_test/global_suites.h b/include/xrpl/beast/unit_test/global_suites.h
index 0492d5fb4b..68b4e2ced8 100644
--- a/include/xrpl/beast/unit_test/global_suites.h
+++ b/include/xrpl/beast/unit_test/global_suites.h
@@ -2,8 +2,7 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#ifndef BEAST_UNIT_TEST_GLOBAL_SUITES_HPP
-#define BEAST_UNIT_TEST_GLOBAL_SUITES_HPP
+#pragma once
 
 #include <xrpl/beast/unit_test/suite_list.h>
 
@@ -40,5 +39,3 @@ global_suites()
 
 }  // namespace unit_test
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/unit_test/match.h b/include/xrpl/beast/unit_test/match.h
index d88ccb7497..38816bb5c7 100644
--- a/include/xrpl/beast/unit_test/match.h
+++ b/include/xrpl/beast/unit_test/match.h
@@ -2,8 +2,7 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#ifndef BEAST_UNIT_TEST_MATCH_HPP
-#define BEAST_UNIT_TEST_MATCH_HPP
+#pragma once
 
 #include <xrpl/beast/unit_test/suite_info.h>
 
@@ -166,5 +165,3 @@ match_library(std::string const& name)
 
 }  // namespace unit_test
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/unit_test/recorder.h b/include/xrpl/beast/unit_test/recorder.h
index 78b376f519..8f956fda88 100644
--- a/include/xrpl/beast/unit_test/recorder.h
+++ b/include/xrpl/beast/unit_test/recorder.h
@@ -2,8 +2,7 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#ifndef BEAST_UNIT_TEST_RECORDER_HPP
-#define BEAST_UNIT_TEST_RECORDER_HPP
+#pragma once
 
 #include <xrpl/beast/unit_test/results.h>
 #include <xrpl/beast/unit_test/runner.h>
@@ -76,5 +75,3 @@ private:
 
 }  // namespace unit_test
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/unit_test/reporter.h b/include/xrpl/beast/unit_test/reporter.h
index adec49c8d4..ee7168d039 100644
--- a/include/xrpl/beast/unit_test/reporter.h
+++ b/include/xrpl/beast/unit_test/reporter.h
@@ -2,8 +2,7 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#ifndef BEAST_UNIT_TEST_REPORTER_HPP
-#define BEAST_UNIT_TEST_REPORTER_HPP
+#pragma once
 
 #include <xrpl/beast/unit_test/amount.h>
 #include <xrpl/beast/unit_test/recorder.h>
@@ -248,5 +247,3 @@ using reporter = detail::reporter<>;
 
 }  // namespace unit_test
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/unit_test/results.h b/include/xrpl/beast/unit_test/results.h
index 478812eff9..cbd0a71057 100644
--- a/include/xrpl/beast/unit_test/results.h
+++ b/include/xrpl/beast/unit_test/results.h
@@ -2,8 +2,7 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#ifndef BEAST_UNIT_TEST_RESULTS_HPP
-#define BEAST_UNIT_TEST_RESULTS_HPP
+#pragma once
 
 #include <xrpl/beast/unit_test/detail/const_container.h>
 
@@ -222,5 +221,3 @@ public:
 
 }  // namespace unit_test
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/unit_test/runner.h b/include/xrpl/beast/unit_test/runner.h
index f91cc92c91..90d8a2f4b5 100644
--- a/include/xrpl/beast/unit_test/runner.h
+++ b/include/xrpl/beast/unit_test/runner.h
@@ -2,8 +2,7 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#ifndef BEAST_UNIT_TEST_RUNNER_H_INCLUDED
-#define BEAST_UNIT_TEST_RUNNER_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/unit_test/suite_info.h>
 
@@ -276,5 +275,3 @@ runner::log(std::string const& s)
 
 }  // namespace unit_test
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/unit_test/suite.h b/include/xrpl/beast/unit_test/suite.h
index 70c2d49fbd..0e6b592a87 100644
--- a/include/xrpl/beast/unit_test/suite.h
+++ b/include/xrpl/beast/unit_test/suite.h
@@ -2,8 +2,7 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#ifndef BEAST_UNIT_TEST_SUITE_HPP
-#define BEAST_UNIT_TEST_SUITE_HPP
+#pragma once
 
 #include <xrpl/beast/unit_test/runner.h>
 
@@ -642,5 +641,3 @@ suite::run(runner& r)
 #endif
 
 //------------------------------------------------------------------------------
-
-#endif
diff --git a/include/xrpl/beast/unit_test/suite_info.h b/include/xrpl/beast/unit_test/suite_info.h
index 5297c0e807..019251b0c4 100644
--- a/include/xrpl/beast/unit_test/suite_info.h
+++ b/include/xrpl/beast/unit_test/suite_info.h
@@ -2,8 +2,7 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#ifndef BEAST_UNIT_TEST_SUITE_INFO_HPP
-#define BEAST_UNIT_TEST_SUITE_INFO_HPP
+#pragma once
 
 #include <cstring>
 #include <functional>
@@ -100,5 +99,3 @@ make_suite_info(std::string name, std::string module, std::string library, bool
 
 }  // namespace unit_test
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/unit_test/suite_list.h b/include/xrpl/beast/unit_test/suite_list.h
index 49bf37cbc6..4412883e31 100644
--- a/include/xrpl/beast/unit_test/suite_list.h
+++ b/include/xrpl/beast/unit_test/suite_list.h
@@ -2,8 +2,7 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#ifndef BEAST_UNIT_TEST_SUITE_LIST_HPP
-#define BEAST_UNIT_TEST_SUITE_LIST_HPP
+#pragma once
 
 #include <xrpl/beast/unit_test/detail/const_container.h>
 #include <xrpl/beast/unit_test/suite_info.h>
@@ -60,5 +59,3 @@ suite_list::insert(char const* name, char const* module, char const* library, bo
 
 }  // namespace unit_test
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/unit_test/thread.h b/include/xrpl/beast/unit_test/thread.h
index 27c3f85920..b49f8ed36e 100644
--- a/include/xrpl/beast/unit_test/thread.h
+++ b/include/xrpl/beast/unit_test/thread.h
@@ -2,8 +2,7 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#ifndef BEAST_UNIT_TEST_THREAD_HPP
-#define BEAST_UNIT_TEST_THREAD_HPP
+#pragma once
 
 #include <xrpl/beast/unit_test/suite.h>
 
@@ -111,5 +110,3 @@ private:
 
 }  // namespace unit_test
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/utility/Journal.h b/include/xrpl/beast/utility/Journal.h
index 7eaf4a627a..dff88826ce 100644
--- a/include/xrpl/beast/utility/Journal.h
+++ b/include/xrpl/beast/utility/Journal.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_UTILITY_JOURNAL_H_INCLUDED
-#define BEAST_UTILITY_JOURNAL_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/instrumentation.h>
 
@@ -431,5 +430,3 @@ using logstream = basic_logstream<char>;
 using logwstream = basic_logstream<wchar_t>;
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/utility/PropertyStream.h b/include/xrpl/beast/utility/PropertyStream.h
index de1fc567f3..3d29138a12 100644
--- a/include/xrpl/beast/utility/PropertyStream.h
+++ b/include/xrpl/beast/utility/PropertyStream.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_UTILITY_PROPERTYSTREAM_H_INCLUDED
-#define BEAST_UTILITY_PROPERTYSTREAM_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/core/List.h>
 
@@ -408,5 +407,3 @@ public:
 };
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/utility/WrappedSink.h b/include/xrpl/beast/utility/WrappedSink.h
index 7819134e01..bb8a1a6994 100644
--- a/include/xrpl/beast/utility/WrappedSink.h
+++ b/include/xrpl/beast/utility/WrappedSink.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_UTILITY_WRAPPEDSINK_H_INCLUDED
-#define BEAST_UTILITY_WRAPPEDSINK_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/Journal.h>
 
@@ -80,5 +79,3 @@ public:
 };
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/utility/Zero.h b/include/xrpl/beast/utility/Zero.h
index fbafc59a81..00e91a1a47 100644
--- a/include/xrpl/beast/utility/Zero.h
+++ b/include/xrpl/beast/utility/Zero.h
@@ -1,7 +1,6 @@
 // Copyright (c) 2014, Tom Ritchford <tom@swirly.com>
 
-#ifndef BEAST_UTILITY_ZERO_H_INCLUDED
-#define BEAST_UTILITY_ZERO_H_INCLUDED
+#pragma once
 
 namespace beast {
 
@@ -144,5 +143,3 @@ operator<=(Zero, T const& t)
 }
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/utility/instrumentation.h b/include/xrpl/beast/utility/instrumentation.h
index b2dcd23a3a..0d0b2ce415 100644
--- a/include/xrpl/beast/utility/instrumentation.h
+++ b/include/xrpl/beast/utility/instrumentation.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_UTILITY_INSTRUMENTATION_H_INCLUDED
-#define BEAST_UTILITY_INSTRUMENTATION_H_INCLUDED
+#pragma once
 
 #include <cassert>
 
@@ -51,5 +50,3 @@
 // instrumentation macros - its name describes the condition which was _not_
 // meant to happen, while name in other macros describes the condition that is
 // meant to happen (e.g. as in "assert that this happens").
-
-#endif
diff --git a/include/xrpl/beast/utility/maybe_const.h b/include/xrpl/beast/utility/maybe_const.h
index 6c577d3c76..4aac7f018e 100644
--- a/include/xrpl/beast/utility/maybe_const.h
+++ b/include/xrpl/beast/utility/maybe_const.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_UTILITY_MAYBE_CONST_H_INCLUDED
-#define BEAST_UTILITY_MAYBE_CONST_H_INCLUDED
+#pragma once
 
 #include <type_traits>
 
@@ -19,5 +18,3 @@ template <bool IsConst, class T>
 using maybe_const_t = typename maybe_const<IsConst, T>::type;
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/utility/rngfill.h b/include/xrpl/beast/utility/rngfill.h
index ba596b789b..7c694aac4f 100644
--- a/include/xrpl/beast/utility/rngfill.h
+++ b/include/xrpl/beast/utility/rngfill.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_RANDOM_RNGFILL_H_INCLUDED
-#define BEAST_RANDOM_RNGFILL_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/instrumentation.h>
 
@@ -48,5 +47,3 @@ rngfill(std::array<std::uint8_t, N>& a, Generator& g)
 }
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/utility/temp_dir.h b/include/xrpl/beast/utility/temp_dir.h
index 37f26b7fec..5aa7b28ac2 100644
--- a/include/xrpl/beast/utility/temp_dir.h
+++ b/include/xrpl/beast/utility/temp_dir.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_UTILITY_TEMP_DIR_H_INCLUDED
-#define BEAST_UTILITY_TEMP_DIR_H_INCLUDED
+#pragma once
 
 #include <boost/filesystem.hpp>
 
@@ -62,5 +61,3 @@ public:
 };
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/beast/xor_shift_engine.h b/include/xrpl/beast/xor_shift_engine.h
index 7eab82ff43..d49cb08fc0 100644
--- a/include/xrpl/beast/xor_shift_engine.h
+++ b/include/xrpl/beast/xor_shift_engine.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_RANDOM_XOR_SHIFT_ENGINE_H_INCLUDED
-#define BEAST_RANDOM_XOR_SHIFT_ENGINE_H_INCLUDED
+#pragma once
 
 #include <cstdint>
 #include <limits>
@@ -95,5 +94,3 @@ xor_shift_engine<_>::murmurhash3(result_type x) -> result_type
 using xor_shift_engine = detail::xor_shift_engine<>;
 
 }  // namespace beast
-
-#endif
diff --git a/include/xrpl/core/ClosureCounter.h b/include/xrpl/core/ClosureCounter.h
index 4127960276..6802a03f3d 100644
--- a/include/xrpl/core/ClosureCounter.h
+++ b/include/xrpl/core/ClosureCounter.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CORE_CLOSURE_COUNTER_H_INCLUDED
-#define XRPL_CORE_CLOSURE_COUNTER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Log.h>
 
@@ -198,5 +197,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif  // XRPL_CORE_CLOSURE_COUNTER_H_INCLUDED
diff --git a/include/xrpl/core/Coro.ipp b/include/xrpl/core/Coro.ipp
index 40067a77e9..2853adf0de 100644
--- a/include/xrpl/core/Coro.ipp
+++ b/include/xrpl/core/Coro.ipp
@@ -1,5 +1,4 @@
-#ifndef XRPL_CORE_COROINL_H_INCLUDED
-#define XRPL_CORE_COROINL_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/ByteUtilities.h>
 
@@ -120,5 +119,3 @@ JobQueue::Coro::join()
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/core/Job.h b/include/xrpl/core/Job.h
index dd60391635..61651fd673 100644
--- a/include/xrpl/core/Job.h
+++ b/include/xrpl/core/Job.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CORE_JOB_H_INCLUDED
-#define XRPL_CORE_JOB_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/core/ClosureCounter.h>
@@ -128,5 +127,3 @@ private:
 using JobCounter = ClosureCounter<void>;
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/core/JobQueue.h b/include/xrpl/core/JobQueue.h
index 48c92146f2..b410e200e1 100644
--- a/include/xrpl/core/JobQueue.h
+++ b/include/xrpl/core/JobQueue.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CORE_JOBQUEUE_H_INCLUDED
-#define XRPL_CORE_JOBQUEUE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/LocalValue.h>
 #include <xrpl/core/ClosureCounter.h>
@@ -402,5 +401,3 @@ JobQueue::postCoro(JobType t, std::string const& name, F&& f)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/core/JobTypeData.h b/include/xrpl/core/JobTypeData.h
index e15e161e0e..cdcb19c316 100644
--- a/include/xrpl/core/JobTypeData.h
+++ b/include/xrpl/core/JobTypeData.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CORE_JOBTYPEDATA_H_INCLUDED
-#define XRPL_CORE_JOBTYPEDATA_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/beast/insight/Collector.h>
@@ -75,5 +74,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/core/JobTypeInfo.h b/include/xrpl/core/JobTypeInfo.h
index e9525fed81..d4daa1ec68 100644
--- a/include/xrpl/core/JobTypeInfo.h
+++ b/include/xrpl/core/JobTypeInfo.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CORE_JOBTYPEINFO_H_INCLUDED
-#define XRPL_CORE_JOBTYPEINFO_H_INCLUDED
+#pragma once
 
 #include <xrpl/core/Job.h>
 
@@ -75,5 +74,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/core/JobTypes.h b/include/xrpl/core/JobTypes.h
index 4a779507f1..88f98aad66 100644
--- a/include/xrpl/core/JobTypes.h
+++ b/include/xrpl/core/JobTypes.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CORE_JOBTYPES_H_INCLUDED
-#define XRPL_CORE_JOBTYPES_H_INCLUDED
+#pragma once
 
 #include <xrpl/core/Job.h>
 #include <xrpl/core/JobTypeInfo.h>
@@ -160,5 +159,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/core/LoadEvent.h b/include/xrpl/core/LoadEvent.h
index 8422fe883e..f94e1020bf 100644
--- a/include/xrpl/core/LoadEvent.h
+++ b/include/xrpl/core/LoadEvent.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CORE_LOADEVENT_H_INCLUDED
-#define XRPL_CORE_LOADEVENT_H_INCLUDED
+#pragma once
 
 #include <chrono>
 #include <string>
@@ -66,5 +65,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/core/LoadMonitor.h b/include/xrpl/core/LoadMonitor.h
index 3b79a0ea23..71fbf75d68 100644
--- a/include/xrpl/core/LoadMonitor.h
+++ b/include/xrpl/core/LoadMonitor.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CORE_LOADMONITOR_H_INCLUDED
-#define XRPL_CORE_LOADMONITOR_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/UptimeClock.h>
 #include <xrpl/beast/utility/Journal.h>
@@ -66,5 +65,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/core/PerfLog.h b/include/xrpl/core/PerfLog.h
index bc788f86b8..eebd41ae09 100644
--- a/include/xrpl/core/PerfLog.h
+++ b/include/xrpl/core/PerfLog.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CORE_PERFLOG_H
-#define XRPL_CORE_PERFLOG_H
+#pragma once
 
 #include <xrpl/basics/BasicConfig.h>
 #include <xrpl/core/JobTypes.h>
@@ -178,5 +177,3 @@ measureDurationAndLog(
 
 }  // namespace perf
 }  // namespace xrpl
-
-#endif  // XRPL_CORE_PERFLOG_H
diff --git a/include/xrpl/core/ServiceRegistry.h b/include/xrpl/core/ServiceRegistry.h
index a70d96292c..7147242339 100644
--- a/include/xrpl/core/ServiceRegistry.h
+++ b/include/xrpl/core/ServiceRegistry.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CORE_SERVICEREGISTRY_H_INCLUDED
-#define XRPL_CORE_SERVICEREGISTRY_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Blob.h>
 #include <xrpl/basics/SHAMapHash.h>
@@ -198,5 +197,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/core/detail/Workers.h b/include/xrpl/core/detail/Workers.h
index 185586e859..c5df622fa1 100644
--- a/include/xrpl/core/detail/Workers.h
+++ b/include/xrpl/core/detail/Workers.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CORE_WORKERS_H_INCLUDED
-#define XRPL_CORE_WORKERS_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/core/LockFreeStack.h>
 #include <xrpl/core/detail/semaphore.h>
@@ -208,5 +207,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/core/detail/semaphore.h b/include/xrpl/core/detail/semaphore.h
index 4249b3b860..fad3bf5e29 100644
--- a/include/xrpl/core/detail/semaphore.h
+++ b/include/xrpl/core/detail/semaphore.h
@@ -26,8 +26,7 @@
  * version is updated.
  */
 
-#ifndef XRPL_CORE_SEMAPHORE_H_INCLUDED
-#define XRPL_CORE_SEMAPHORE_H_INCLUDED
+#pragma once
 
 #include <condition_variable>
 #include <mutex>
@@ -88,5 +87,3 @@ public:
 using semaphore = basic_semaphore<std::mutex, std::condition_variable>;
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/crypto/RFC1751.h b/include/xrpl/crypto/RFC1751.h
index a413c2ac8a..64b3e08813 100644
--- a/include/xrpl/crypto/RFC1751.h
+++ b/include/xrpl/crypto/RFC1751.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CRYPTO_RFC1751_H_INCLUDED
-#define XRPL_CRYPTO_RFC1751_H_INCLUDED
+#pragma once
 
 #include <string>
 #include <vector>
@@ -43,5 +42,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/crypto/csprng.h b/include/xrpl/crypto/csprng.h
index dc89da4f61..e5135c96d7 100644
--- a/include/xrpl/crypto/csprng.h
+++ b/include/xrpl/crypto/csprng.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CRYPTO_RANDOM_H_INCLUDED
-#define XRPL_CRYPTO_RANDOM_H_INCLUDED
+#pragma once
 
 #include <mutex>
 
@@ -71,5 +70,3 @@ csprng_engine&
 crypto_prng();
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/crypto/secure_erase.h b/include/xrpl/crypto/secure_erase.h
index 3ecde0c7fa..2815a8531a 100644
--- a/include/xrpl/crypto/secure_erase.h
+++ b/include/xrpl/crypto/secure_erase.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CRYPTO_SECURE_ERASE_H_INCLUDED
-#define XRPL_CRYPTO_SECURE_ERASE_H_INCLUDED
+#pragma once
 
 #include <cstddef>
 
@@ -23,5 +22,3 @@ void
 secure_erase(void* dest, std::size_t bytes);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/json/JsonPropertyStream.h b/include/xrpl/json/JsonPropertyStream.h
index 54cfcbfa04..510ed72950 100644
--- a/include/xrpl/json/JsonPropertyStream.h
+++ b/include/xrpl/json/JsonPropertyStream.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_JSON_JSONPROPERTYSTREAM_H_INCLUDED
-#define XRPL_JSON_JSONPROPERTYSTREAM_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/PropertyStream.h>
 #include <xrpl/json/json_value.h>
@@ -67,5 +66,3 @@ protected:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/json/Output.h b/include/xrpl/json/Output.h
index db990ab364..b0ba3fa6d4 100644
--- a/include/xrpl/json/Output.h
+++ b/include/xrpl/json/Output.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_JSON_OUTPUT_H_INCLUDED
-#define XRPL_JSON_OUTPUT_H_INCLUDED
+#pragma once
 
 #include <boost/beast/core/string.hpp>
 
@@ -35,5 +34,3 @@ std::string
 jsonAsString(Json::Value const&);
 
 }  // namespace Json
-
-#endif
diff --git a/include/xrpl/json/Writer.h b/include/xrpl/json/Writer.h
index ab52427a5b..e348e57825 100644
--- a/include/xrpl/json/Writer.h
+++ b/include/xrpl/json/Writer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_JSON_WRITER_H_INCLUDED
-#define XRPL_JSON_WRITER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/ToString.h>
 #include <xrpl/basics/contract.h>
@@ -238,5 +237,3 @@ check(bool condition, std::string const& message)
 }
 
 }  // namespace Json
-
-#endif
diff --git a/include/xrpl/json/detail/json_assert.h b/include/xrpl/json/detail/json_assert.h
index 3092b65452..e9a66ccef1 100644
--- a/include/xrpl/json/detail/json_assert.h
+++ b/include/xrpl/json/detail/json_assert.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_JSON_JSON_ASSERT_H_INCLUDED
-#define XRPL_JSON_JSON_ASSERT_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/contract.h>
 #include <xrpl/json/json_errors.h>
@@ -7,5 +6,3 @@
 #define JSON_ASSERT_MESSAGE(condition, message) \
     if (!(condition))                           \
         xrpl::Throw<Json::error>(message);
-
-#endif
diff --git a/include/xrpl/json/json_errors.h b/include/xrpl/json/json_errors.h
index a63637b116..5cbf3bd2a5 100644
--- a/include/xrpl/json/json_errors.h
+++ b/include/xrpl/json/json_errors.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_JSON_JSON_ERRORS_H_INCLUDED
-#define XRPL_JSON_JSON_ERRORS_H_INCLUDED
+#pragma once
 
 #include <stdexcept>
 
@@ -11,5 +10,3 @@ struct error : std::runtime_error
 };
 
 }  // namespace Json
-
-#endif  // JSON_FORWARDS_H_INCLUDED
diff --git a/include/xrpl/json/json_forwards.h b/include/xrpl/json/json_forwards.h
index 7a6c444660..612648a5f4 100644
--- a/include/xrpl/json/json_forwards.h
+++ b/include/xrpl/json/json_forwards.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_JSON_JSON_FORWARDS_H_INCLUDED
-#define XRPL_JSON_JSON_FORWARDS_H_INCLUDED
+#pragma once
 
 namespace Json {
 
@@ -13,5 +12,3 @@ class ValueIterator;
 class ValueConstIterator;
 
 }  // namespace Json
-
-#endif  // JSON_FORWARDS_H_INCLUDED
diff --git a/include/xrpl/json/json_reader.h b/include/xrpl/json/json_reader.h
index 814d62dd88..3a1bc38929 100644
--- a/include/xrpl/json/json_reader.h
+++ b/include/xrpl/json/json_reader.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_JSON_JSON_READER_H_INCLUDED
-#define XRPL_JSON_JSON_READER_H_INCLUDED
+#pragma once
 
 #include <xrpl/json/json_forwards.h>
 #include <xrpl/json/json_value.h>
@@ -217,5 +216,3 @@ std::istream&
 operator>>(std::istream&, Value&);
 
 }  // namespace Json
-
-#endif  // XRPL_JSON_JSON_READER_H_INCLUDED
diff --git a/include/xrpl/json/json_value.h b/include/xrpl/json/json_value.h
index 4a7b1d869a..5895c94065 100644
--- a/include/xrpl/json/json_value.h
+++ b/include/xrpl/json/json_value.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_JSON_JSON_VALUE_H_INCLUDED
-#define XRPL_JSON_JSON_VALUE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Number.h>
 #include <xrpl/json/json_forwards.h>
@@ -677,5 +676,3 @@ public:
 };
 
 }  // namespace Json
-
-#endif  // XRPL_JSON_JSON_VALUE_H_INCLUDED
diff --git a/include/xrpl/json/json_writer.h b/include/xrpl/json/json_writer.h
index 9049520a98..9455d4abd9 100644
--- a/include/xrpl/json/json_writer.h
+++ b/include/xrpl/json/json_writer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_JSON_JSON_WRITER_H_INCLUDED
-#define XRPL_JSON_JSON_WRITER_H_INCLUDED
+#pragma once
 
 #include <xrpl/json/json_forwards.h>
 #include <xrpl/json/json_value.h>
@@ -322,5 +321,3 @@ public:
 };
 
 }  // namespace Json
-
-#endif  // JSON_WRITER_H_INCLUDED
diff --git a/include/xrpl/json/to_string.h b/include/xrpl/json/to_string.h
index a930c29231..fb379f5759 100644
--- a/include/xrpl/json/to_string.h
+++ b/include/xrpl/json/to_string.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_JSON_TO_STRING_H_INCLUDED
-#define XRPL_JSON_TO_STRING_H_INCLUDED
+#pragma once
 
 #include <ostream>
 #include <string>
@@ -21,5 +20,3 @@ std::ostream&
 operator<<(std::ostream&, Value const& root);
 
 }  // namespace Json
-
-#endif  // JSON_TO_STRING_H_INCLUDED
diff --git a/include/xrpl/ledger/ApplyView.h b/include/xrpl/ledger/ApplyView.h
index c2eabf00bd..2de5f79452 100644
--- a/include/xrpl/ledger/ApplyView.h
+++ b/include/xrpl/ledger/ApplyView.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_LEDGER_APPLYVIEW_H_INCLUDED
-#define XRPL_LEDGER_APPLYVIEW_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/safe_cast.h>
 #include <xrpl/beast/utility/instrumentation.h>
@@ -382,5 +381,3 @@ insertPage(
 
 }  // namespace directory
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/ledger/ApplyViewImpl.h b/include/xrpl/ledger/ApplyViewImpl.h
index c2b824f196..f6c83462f2 100644
--- a/include/xrpl/ledger/ApplyViewImpl.h
+++ b/include/xrpl/ledger/ApplyViewImpl.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_LEDGER_APPLYVIEWIMPL_H_INCLUDED
-#define XRPL_LEDGER_APPLYVIEWIMPL_H_INCLUDED
+#pragma once
 
 #include <xrpl/ledger/OpenView.h>
 #include <xrpl/ledger/detail/ApplyViewBase.h>
@@ -70,5 +69,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/ledger/BookDirs.h b/include/xrpl/ledger/BookDirs.h
index 23b9557f37..eb1cbcbfa7 100644
--- a/include/xrpl/ledger/BookDirs.h
+++ b/include/xrpl/ledger/BookDirs.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_LEDGER_BOOK_DIRS_H_INCLUDED
-#define XRPL_LEDGER_BOOK_DIRS_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/Journal.h>
 #include <xrpl/ledger/ReadView.h>
@@ -87,5 +86,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/ledger/CachedSLEs.h b/include/xrpl/ledger/CachedSLEs.h
index b478b78b7d..2909501b1d 100644
--- a/include/xrpl/ledger/CachedSLEs.h
+++ b/include/xrpl/ledger/CachedSLEs.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_LEDGER_CACHEDSLES_H_INCLUDED
-#define XRPL_LEDGER_CACHEDSLES_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/TaggedCache.h>
 #include <xrpl/basics/base_uint.h>
@@ -8,5 +7,3 @@
 namespace xrpl {
 using CachedSLEs = TaggedCache<uint256, SLE const>;
 }
-
-#endif  // XRPL_LEDGER_CACHEDSLES_H_INCLUDED
diff --git a/include/xrpl/ledger/CachedView.h b/include/xrpl/ledger/CachedView.h
index 9a93c5f743..7cab1dc1b3 100644
--- a/include/xrpl/ledger/CachedView.h
+++ b/include/xrpl/ledger/CachedView.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_LEDGER_CACHEDVIEW_H_INCLUDED
-#define XRPL_LEDGER_CACHEDVIEW_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/hardened_hash.h>
 #include <xrpl/ledger/CachedSLEs.h>
@@ -162,5 +161,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/ledger/CredentialHelpers.h b/include/xrpl/ledger/CredentialHelpers.h
index 09b4d63da0..3744ff47eb 100644
--- a/include/xrpl/ledger/CredentialHelpers.h
+++ b/include/xrpl/ledger/CredentialHelpers.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_CREDENTIALHELPERS_H_INCLUDED
-#define XRPL_APP_MISC_CREDENTIALHELPERS_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/basics/base_uint.h>
@@ -79,5 +78,3 @@ verifyDepositPreauth(
     beast::Journal j);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/ledger/Credit.h b/include/xrpl/ledger/Credit.h
index e64c6015aa..58ec23a86a 100644
--- a/include/xrpl/ledger/Credit.h
+++ b/include/xrpl/ledger/Credit.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_LEDGER_CREDIT_H_INCLUDED
-#define XRPL_LEDGER_CREDIT_H_INCLUDED
+#pragma once
 
 #include <xrpl/ledger/View.h>
 #include <xrpl/protocol/IOUAmount.h>
@@ -34,5 +33,3 @@ creditBalance(ReadView const& view, AccountID const& account, AccountID const& i
 /** @} */
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/ledger/Dir.h b/include/xrpl/ledger/Dir.h
index 4b7327a015..0c2f1e3765 100644
--- a/include/xrpl/ledger/Dir.h
+++ b/include/xrpl/ledger/Dir.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_LEDGER_DIR_H_INCLUDED
-#define XRPL_LEDGER_DIR_H_INCLUDED
+#pragma once
 
 #include <xrpl/ledger/ReadView.h>
 #include <xrpl/protocol/Indexes.h>
@@ -109,5 +108,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/ledger/OpenView.h b/include/xrpl/ledger/OpenView.h
index 5441d35a0e..42f62d5bca 100644
--- a/include/xrpl/ledger/OpenView.h
+++ b/include/xrpl/ledger/OpenView.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_LEDGER_OPENVIEW_H_INCLUDED
-#define XRPL_LEDGER_OPENVIEW_H_INCLUDED
+#pragma once
 
 #include <xrpl/ledger/RawView.h>
 #include <xrpl/ledger/ReadView.h>
@@ -240,5 +239,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/ledger/PaymentSandbox.h b/include/xrpl/ledger/PaymentSandbox.h
index fd77d154d8..fe62d753ec 100644
--- a/include/xrpl/ledger/PaymentSandbox.h
+++ b/include/xrpl/ledger/PaymentSandbox.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_LEDGER_PAYMENTSANDBOX_H_INCLUDED
-#define XRPL_LEDGER_PAYMENTSANDBOX_H_INCLUDED
+#pragma once
 
 #include <xrpl/ledger/RawView.h>
 #include <xrpl/ledger/Sandbox.h>
@@ -172,5 +171,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/ledger/RawView.h b/include/xrpl/ledger/RawView.h
index c0e81fb833..cfcf807e13 100644
--- a/include/xrpl/ledger/RawView.h
+++ b/include/xrpl/ledger/RawView.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_LEDGER_RAWVIEW_H_INCLUDED
-#define XRPL_LEDGER_RAWVIEW_H_INCLUDED
+#pragma once
 
 #include <xrpl/ledger/ReadView.h>
 #include <xrpl/protocol/STLedgerEntry.h>
@@ -88,5 +87,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/ledger/ReadView.h b/include/xrpl/ledger/ReadView.h
index 5e33e7b4ba..faec10993a 100644
--- a/include/xrpl/ledger/ReadView.h
+++ b/include/xrpl/ledger/ReadView.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_LEDGER_READVIEW_H_INCLUDED
-#define XRPL_LEDGER_READVIEW_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/chrono.h>
 #include <xrpl/beast/hash/uhash.h>
@@ -253,5 +252,3 @@ makeRulesGivenLedger(DigestAwareReadView const& ledger, std::unordered_set<uint2
 }  // namespace xrpl
 
 #include <xrpl/ledger/detail/ReadViewFwdRange.ipp>
-
-#endif
diff --git a/include/xrpl/ledger/Sandbox.h b/include/xrpl/ledger/Sandbox.h
index 1e4a816529..dc80df5ba2 100644
--- a/include/xrpl/ledger/Sandbox.h
+++ b/include/xrpl/ledger/Sandbox.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_LEDGER_SANDBOX_H_INCLUDED
-#define XRPL_LEDGER_SANDBOX_H_INCLUDED
+#pragma once
 
 #include <xrpl/ledger/RawView.h>
 #include <xrpl/ledger/detail/ApplyViewBase.h>
@@ -40,5 +39,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/ledger/View.h b/include/xrpl/ledger/View.h
index 7bf833fbad..fa16e16006 100644
--- a/include/xrpl/ledger/View.h
+++ b/include/xrpl/ledger/View.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_LEDGER_VIEW_H_INCLUDED
-#define XRPL_LEDGER_VIEW_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/Journal.h>
 #include <xrpl/ledger/ApplyView.h>
@@ -996,5 +995,3 @@ bool
 after(NetClock::time_point now, std::uint32_t mark);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/ledger/detail/ApplyStateTable.h b/include/xrpl/ledger/detail/ApplyStateTable.h
index 9fb7b64fe8..07af5247f6 100644
--- a/include/xrpl/ledger/detail/ApplyStateTable.h
+++ b/include/xrpl/ledger/detail/ApplyStateTable.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_LEDGER_APPLYSTATETABLE_H_INCLUDED
-#define XRPL_LEDGER_APPLYSTATETABLE_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/Journal.h>
 #include <xrpl/ledger/OpenView.h>
@@ -128,5 +127,3 @@ private:
 
 }  // namespace detail
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/ledger/detail/ApplyViewBase.h b/include/xrpl/ledger/detail/ApplyViewBase.h
index 9c048c6d90..b3ec3c0fea 100644
--- a/include/xrpl/ledger/detail/ApplyViewBase.h
+++ b/include/xrpl/ledger/detail/ApplyViewBase.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_LEDGER_APPLYVIEWBASE_H_INCLUDED
-#define XRPL_LEDGER_APPLYVIEWBASE_H_INCLUDED
+#pragma once
 
 #include <xrpl/ledger/ApplyView.h>
 #include <xrpl/ledger/ReadView.h>
@@ -105,5 +104,3 @@ protected:
 
 }  // namespace detail
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/ledger/detail/RawStateTable.h b/include/xrpl/ledger/detail/RawStateTable.h
index 881d00be53..e09f2f0e44 100644
--- a/include/xrpl/ledger/detail/RawStateTable.h
+++ b/include/xrpl/ledger/detail/RawStateTable.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_LEDGER_RAWSTATETABLE_H_INCLUDED
-#define XRPL_LEDGER_RAWSTATETABLE_H_INCLUDED
+#pragma once
 
 #include <xrpl/ledger/RawView.h>
 #include <xrpl/ledger/ReadView.h>
@@ -109,5 +108,3 @@ private:
 
 }  // namespace detail
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/ledger/detail/ReadViewFwdRange.h b/include/xrpl/ledger/detail/ReadViewFwdRange.h
index 05d2b79a50..bf40b04a6a 100644
--- a/include/xrpl/ledger/detail/ReadViewFwdRange.h
+++ b/include/xrpl/ledger/detail/ReadViewFwdRange.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_LEDGER_READVIEWFWDRANGE_H_INCLUDED
-#define XRPL_LEDGER_READVIEWFWDRANGE_H_INCLUDED
+#pragma once
 
 #include <cstddef>
 #include <memory>
@@ -129,5 +128,3 @@ protected:
 
 }  // namespace detail
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/ledger/detail/ReadViewFwdRange.ipp b/include/xrpl/ledger/detail/ReadViewFwdRange.ipp
index 6978d3abad..212be52432 100644
--- a/include/xrpl/ledger/detail/ReadViewFwdRange.ipp
+++ b/include/xrpl/ledger/detail/ReadViewFwdRange.ipp
@@ -1,5 +1,4 @@
-#ifndef XRPL_LEDGER_READVIEWFWDRANGEINL_H_INCLUDED
-#define XRPL_LEDGER_READVIEWFWDRANGEINL_H_INCLUDED
+#pragma once
 
 namespace xrpl {
 namespace detail {
@@ -108,5 +107,3 @@ ReadViewFwdRange<ValueType>::iterator::operator++(int) -> iterator
 
 }  // namespace detail
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/net/AutoSocket.h b/include/xrpl/net/AutoSocket.h
index da4d3c30e5..85a3adb456 100644
--- a/include/xrpl/net/AutoSocket.h
+++ b/include/xrpl/net/AutoSocket.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_WEBSOCKET_AUTOSOCKET_AUTOSOCKET_H_INCLUDED
-#define XRPL_WEBSOCKET_AUTOSOCKET_AUTOSOCKET_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/beast/net/IPAddressConversion.h>
@@ -268,5 +267,3 @@ private:
     std::vector<char> mBuffer;
     beast::Journal j_;
 };
-
-#endif
diff --git a/include/xrpl/net/HTTPClient.h b/include/xrpl/net/HTTPClient.h
index 0e1a56e42d..289ce8f6e3 100644
--- a/include/xrpl/net/HTTPClient.h
+++ b/include/xrpl/net/HTTPClient.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NET_HTTPCLIENT_H_INCLUDED
-#define XRPL_NET_HTTPCLIENT_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/ByteUtilities.h>
 #include <xrpl/beast/utility/Journal.h>
@@ -69,5 +68,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/net/HTTPClientSSLContext.h b/include/xrpl/net/HTTPClientSSLContext.h
index f195b031da..1033b9a22b 100644
--- a/include/xrpl/net/HTTPClientSSLContext.h
+++ b/include/xrpl/net/HTTPClientSSLContext.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NET_HTTPCLIENTSSLCONTEXT_H_INCLUDED
-#define XRPL_NET_HTTPCLIENTSSLCONTEXT_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/basics/contract.h>
@@ -148,5 +147,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/net/RegisterSSLCerts.h b/include/xrpl/net/RegisterSSLCerts.h
index 273d1966d1..e313b1cb06 100644
--- a/include/xrpl/net/RegisterSSLCerts.h
+++ b/include/xrpl/net/RegisterSSLCerts.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NET_REGISTER_SSL_CERTS_H_INCLUDED
-#define XRPL_NET_REGISTER_SSL_CERTS_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Log.h>
 
@@ -17,5 +16,3 @@ void
 registerSSLCerts(boost::asio::ssl::context&, boost::system::error_code&, beast::Journal j);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/nodestore/Backend.h b/include/xrpl/nodestore/Backend.h
index d3b995b6ed..6af292d5b3 100644
--- a/include/xrpl/nodestore/Backend.h
+++ b/include/xrpl/nodestore/Backend.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NODESTORE_BACKEND_H_INCLUDED
-#define XRPL_NODESTORE_BACKEND_H_INCLUDED
+#pragma once
 
 #include <xrpl/nodestore/Types.h>
 
@@ -142,5 +141,3 @@ public:
 
 }  // namespace NodeStore
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/nodestore/Database.h b/include/xrpl/nodestore/Database.h
index a1de865241..d3dafff85d 100644
--- a/include/xrpl/nodestore/Database.h
+++ b/include/xrpl/nodestore/Database.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NODESTORE_DATABASE_H_INCLUDED
-#define XRPL_NODESTORE_DATABASE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/BasicConfig.h>
 #include <xrpl/basics/Log.h>
@@ -274,5 +273,3 @@ private:
 
 }  // namespace NodeStore
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/nodestore/DatabaseRotating.h b/include/xrpl/nodestore/DatabaseRotating.h
index 89e2ae8c0c..e20b49805c 100644
--- a/include/xrpl/nodestore/DatabaseRotating.h
+++ b/include/xrpl/nodestore/DatabaseRotating.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NODESTORE_DATABASEROTATING_H_INCLUDED
-#define XRPL_NODESTORE_DATABASEROTATING_H_INCLUDED
+#pragma once
 
 #include <xrpl/nodestore/Database.h>
 
@@ -34,5 +33,3 @@ public:
 
 }  // namespace NodeStore
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/nodestore/DummyScheduler.h b/include/xrpl/nodestore/DummyScheduler.h
index b31613480f..9fce4a6100 100644
--- a/include/xrpl/nodestore/DummyScheduler.h
+++ b/include/xrpl/nodestore/DummyScheduler.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NODESTORE_DUMMYSCHEDULER_H_INCLUDED
-#define XRPL_NODESTORE_DUMMYSCHEDULER_H_INCLUDED
+#pragma once
 
 #include <xrpl/nodestore/Scheduler.h>
 
@@ -22,5 +21,3 @@ public:
 
 }  // namespace NodeStore
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/nodestore/Factory.h b/include/xrpl/nodestore/Factory.h
index d6d33c4b64..e01bdfabf2 100644
--- a/include/xrpl/nodestore/Factory.h
+++ b/include/xrpl/nodestore/Factory.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NODESTORE_FACTORY_H_INCLUDED
-#define XRPL_NODESTORE_FACTORY_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/BasicConfig.h>
 #include <xrpl/beast/utility/Journal.h>
@@ -62,5 +61,3 @@ public:
 
 }  // namespace NodeStore
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/nodestore/Manager.h b/include/xrpl/nodestore/Manager.h
index e6d62fbc4a..9553407881 100644
--- a/include/xrpl/nodestore/Manager.h
+++ b/include/xrpl/nodestore/Manager.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NODESTORE_MANAGER_H_INCLUDED
-#define XRPL_NODESTORE_MANAGER_H_INCLUDED
+#pragma once
 
 #include <xrpl/nodestore/DatabaseRotating.h>
 #include <xrpl/nodestore/Factory.h>
@@ -80,5 +79,3 @@ public:
 
 }  // namespace NodeStore
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/nodestore/NodeObject.h b/include/xrpl/nodestore/NodeObject.h
index 1926d1791c..2274fc8c38 100644
--- a/include/xrpl/nodestore/NodeObject.h
+++ b/include/xrpl/nodestore/NodeObject.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NODESTORE_NODEOBJECT_H_INCLUDED
-#define XRPL_NODESTORE_NODEOBJECT_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Blob.h>
 #include <xrpl/basics/CountedObject.h>
@@ -78,5 +77,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/nodestore/Scheduler.h b/include/xrpl/nodestore/Scheduler.h
index 0835e08fa2..6e01533930 100644
--- a/include/xrpl/nodestore/Scheduler.h
+++ b/include/xrpl/nodestore/Scheduler.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NODESTORE_SCHEDULER_H_INCLUDED
-#define XRPL_NODESTORE_SCHEDULER_H_INCLUDED
+#pragma once
 
 #include <xrpl/nodestore/Task.h>
 
@@ -67,5 +66,3 @@ public:
 
 }  // namespace NodeStore
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/nodestore/Task.h b/include/xrpl/nodestore/Task.h
index bd21e61975..4bfc88bd13 100644
--- a/include/xrpl/nodestore/Task.h
+++ b/include/xrpl/nodestore/Task.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NODESTORE_TASK_H_INCLUDED
-#define XRPL_NODESTORE_TASK_H_INCLUDED
+#pragma once
 
 namespace xrpl {
 namespace NodeStore {
@@ -18,5 +17,3 @@ struct Task
 
 }  // namespace NodeStore
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/nodestore/Types.h b/include/xrpl/nodestore/Types.h
index 6763196860..5adbc40f70 100644
--- a/include/xrpl/nodestore/Types.h
+++ b/include/xrpl/nodestore/Types.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NODESTORE_TYPES_H_INCLUDED
-#define XRPL_NODESTORE_TYPES_H_INCLUDED
+#pragma once
 
 #include <xrpl/nodestore/NodeObject.h>
 
@@ -38,5 +37,3 @@ using Batch = std::vector<std::shared_ptr<NodeObject>>;
 }  // namespace NodeStore
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/nodestore/detail/BatchWriter.h b/include/xrpl/nodestore/detail/BatchWriter.h
index f1faf0a612..1820435133 100644
--- a/include/xrpl/nodestore/detail/BatchWriter.h
+++ b/include/xrpl/nodestore/detail/BatchWriter.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NODESTORE_BATCHWRITER_H_INCLUDED
-#define XRPL_NODESTORE_BATCHWRITER_H_INCLUDED
+#pragma once
 
 #include <xrpl/nodestore/Scheduler.h>
 #include <xrpl/nodestore/Task.h>
@@ -79,5 +78,3 @@ private:
 
 }  // namespace NodeStore
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/nodestore/detail/DatabaseNodeImp.h b/include/xrpl/nodestore/detail/DatabaseNodeImp.h
index 900d6a5a59..dd6b8f9ddd 100644
--- a/include/xrpl/nodestore/detail/DatabaseNodeImp.h
+++ b/include/xrpl/nodestore/detail/DatabaseNodeImp.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NODESTORE_DATABASENODEIMP_H_INCLUDED
-#define XRPL_NODESTORE_DATABASENODEIMP_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/TaggedCache.h>
 #include <xrpl/basics/chrono.h>
@@ -126,5 +125,3 @@ private:
 
 }  // namespace NodeStore
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/nodestore/detail/DatabaseRotatingImp.h b/include/xrpl/nodestore/detail/DatabaseRotatingImp.h
index 31c9ebbaec..e49c195d67 100644
--- a/include/xrpl/nodestore/detail/DatabaseRotatingImp.h
+++ b/include/xrpl/nodestore/detail/DatabaseRotatingImp.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NODESTORE_DATABASEROTATINGIMP_H_INCLUDED
-#define XRPL_NODESTORE_DATABASEROTATINGIMP_H_INCLUDED
+#pragma once
 
 #include <xrpl/nodestore/DatabaseRotating.h>
 
@@ -73,5 +72,3 @@ private:
 
 }  // namespace NodeStore
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/nodestore/detail/DecodedBlob.h b/include/xrpl/nodestore/detail/DecodedBlob.h
index 0eaa169269..dc6704a08d 100644
--- a/include/xrpl/nodestore/detail/DecodedBlob.h
+++ b/include/xrpl/nodestore/detail/DecodedBlob.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NODESTORE_DECODEDBLOB_H_INCLUDED
-#define XRPL_NODESTORE_DECODEDBLOB_H_INCLUDED
+#pragma once
 
 #include <xrpl/nodestore/NodeObject.h>
 
@@ -44,5 +43,3 @@ private:
 
 }  // namespace NodeStore
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/nodestore/detail/EncodedBlob.h b/include/xrpl/nodestore/detail/EncodedBlob.h
index a4c553cf71..78e7153f73 100644
--- a/include/xrpl/nodestore/detail/EncodedBlob.h
+++ b/include/xrpl/nodestore/detail/EncodedBlob.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NODESTORE_ENCODEDBLOB_H_INCLUDED
-#define XRPL_NODESTORE_ENCODEDBLOB_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/nodestore/NodeObject.h>
@@ -107,5 +106,3 @@ public:
 
 }  // namespace NodeStore
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/nodestore/detail/ManagerImp.h b/include/xrpl/nodestore/detail/ManagerImp.h
index eb3ee21db4..f46a7d56d0 100644
--- a/include/xrpl/nodestore/detail/ManagerImp.h
+++ b/include/xrpl/nodestore/detail/ManagerImp.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NODESTORE_MANAGERIMP_H_INCLUDED
-#define XRPL_NODESTORE_MANAGERIMP_H_INCLUDED
+#pragma once
 
 #include <xrpl/nodestore/Manager.h>
 
@@ -48,5 +47,3 @@ public:
 
 }  // namespace NodeStore
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/nodestore/detail/codec.h b/include/xrpl/nodestore/detail/codec.h
index adbf214ce5..1d08beff59 100644
--- a/include/xrpl/nodestore/detail/codec.h
+++ b/include/xrpl/nodestore/detail/codec.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NODESTORE_CODEC_H_INCLUDED
-#define XRPL_NODESTORE_CODEC_H_INCLUDED
+#pragma once
 
 // Disable lz4 deprecation warning due to incompatibility with clang attributes
 #define LZ4_DISABLE_DEPRECATE_WARNINGS
@@ -305,5 +304,3 @@ filter_inner(void* in, std::size_t in_size)
 
 }  // namespace NodeStore
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/nodestore/detail/varint.h b/include/xrpl/nodestore/detail/varint.h
index 7cf9fbaf4b..98f8d8ff08 100644
--- a/include/xrpl/nodestore/detail/varint.h
+++ b/include/xrpl/nodestore/detail/varint.h
@@ -1,5 +1,4 @@
-#ifndef BEAST_NUDB_VARINT_H_INCLUDED
-#define BEAST_NUDB_VARINT_H_INCLUDED
+#pragma once
 
 #include <nudb/detail/stream.hpp>
 
@@ -119,5 +118,3 @@ write(nudb::detail::ostream& os, std::size_t t)
 
 }  // namespace NodeStore
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/AMMCore.h b/include/xrpl/protocol/AMMCore.h
index cdd99c65eb..a2c531f361 100644
--- a/include/xrpl/protocol/AMMCore.h
+++ b/include/xrpl/protocol/AMMCore.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_AMMCORE_H_INCLUDED
-#define XRPL_PROTOCOL_AMMCORE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Number.h>
 #include <xrpl/protocol/AccountID.h>
@@ -97,5 +96,3 @@ feeMultHalf(std::uint16_t tfee)
 }
 
 }  // namespace xrpl
-
-#endif  // XRPL_PROTOCOL_AMMCORE_H_INCLUDED
diff --git a/include/xrpl/protocol/AccountID.h b/include/xrpl/protocol/AccountID.h
index d61938e2a7..bc57058d9e 100644
--- a/include/xrpl/protocol/AccountID.h
+++ b/include/xrpl/protocol/AccountID.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_ACCOUNTID_H_INCLUDED
-#define XRPL_PROTOCOL_ACCOUNTID_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/tokens.h>
 // VFALCO Uncomment when the header issues are resolved
@@ -133,5 +132,3 @@ struct hash<xrpl::AccountID> : xrpl::AccountID::hasher
 };
 
 }  // namespace std
-
-#endif
diff --git a/include/xrpl/protocol/AmountConversions.h b/include/xrpl/protocol/AmountConversions.h
index d4a66c5d94..0807e96c49 100644
--- a/include/xrpl/protocol/AmountConversions.h
+++ b/include/xrpl/protocol/AmountConversions.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_AMOUNTCONVERSION_H_INCLUDED
-#define XRPL_PROTOCOL_AMOUNTCONVERSION_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/IOUAmount.h>
 #include <xrpl/protocol/STAmount.h>
@@ -184,5 +183,3 @@ get(STAmount const& a)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/ApiVersion.h b/include/xrpl/protocol/ApiVersion.h
index b8dc8ecb20..756a41d25e 100644
--- a/include/xrpl/protocol/ApiVersion.h
+++ b/include/xrpl/protocol/ApiVersion.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_APIVERSION_H_INCLUDED
-#define XRPL_PROTOCOL_APIVERSION_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/core/SemanticVersion.h>
 #include <xrpl/beast/utility/instrumentation.h>
@@ -151,5 +150,3 @@ forAllApiVersions(Fn const& fn, Args&&... args)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/Asset.h b/include/xrpl/protocol/Asset.h
index e7852cdefe..d48bc94b50 100644
--- a/include/xrpl/protocol/Asset.h
+++ b/include/xrpl/protocol/Asset.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_ASSET_H_INCLUDED
-#define XRPL_PROTOCOL_ASSET_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Number.h>
 #include <xrpl/basics/base_uint.h>
@@ -225,5 +224,3 @@ Asset
 assetFromJson(Json::Value const& jv);
 
 }  // namespace xrpl
-
-#endif  // XRPL_PROTOCOL_ASSET_H_INCLUDED
diff --git a/include/xrpl/protocol/Book.h b/include/xrpl/protocol/Book.h
index 9e26af9f79..83965cf701 100644
--- a/include/xrpl/protocol/Book.h
+++ b/include/xrpl/protocol/Book.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_BOOK_H_INCLUDED
-#define XRPL_PROTOCOL_BOOK_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/basics/base_uint.h>
@@ -171,5 +170,3 @@ struct hash<xrpl::Book> : std::hash<xrpl::Book>
 };
 
 }  // namespace boost
-
-#endif
diff --git a/include/xrpl/protocol/BuildInfo.h b/include/xrpl/protocol/BuildInfo.h
index 0b75f8b0a1..3c42a4323f 100644
--- a/include/xrpl/protocol/BuildInfo.h
+++ b/include/xrpl/protocol/BuildInfo.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_BUILDINFO_H_INCLUDED
-#define XRPL_PROTOCOL_BUILDINFO_H_INCLUDED
+#pragma once
 
 #include <cstdint>
 #include <string>
@@ -80,5 +79,3 @@ isNewerVersion(std::uint64_t version);
 }  // namespace BuildInfo
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/ErrorCodes.h b/include/xrpl/protocol/ErrorCodes.h
index 172c3fd57f..08c034e38f 100644
--- a/include/xrpl/protocol/ErrorCodes.h
+++ b/include/xrpl/protocol/ErrorCodes.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_ERRORCODES_H_INCLUDED
-#define XRPL_PROTOCOL_ERRORCODES_H_INCLUDED
+#pragma once
 
 #include <xrpl/json/json_value.h>
 #include <xrpl/protocol/jss.h>
@@ -324,5 +323,3 @@ std::string
 rpcErrorString(Json::Value const& jv);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/Feature.h b/include/xrpl/protocol/Feature.h
index fac6627b1c..6d674fbef2 100644
--- a/include/xrpl/protocol/Feature.h
+++ b/include/xrpl/protocol/Feature.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_FEATURE_H_INCLUDED
-#define XRPL_PROTOCOL_FEATURE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/base_uint.h>
 
@@ -361,5 +360,3 @@ foreachFeature(FeatureBitset bs, F&& f)
 #pragma pop_macro("XRPL_FEATURE")
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/Fees.h b/include/xrpl/protocol/Fees.h
index 8c7cb51777..84c8ffe81f 100644
--- a/include/xrpl/protocol/Fees.h
+++ b/include/xrpl/protocol/Fees.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_FEES_H_INCLUDED
-#define XRPL_PROTOCOL_FEES_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/XRPAmount.h>
 
@@ -34,5 +33,3 @@ struct Fees
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/HashPrefix.h b/include/xrpl/protocol/HashPrefix.h
index babba3f7bd..305b4bfd49 100644
--- a/include/xrpl/protocol/HashPrefix.h
+++ b/include/xrpl/protocol/HashPrefix.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_HASHPREFIX_H_INCLUDED
-#define XRPL_PROTOCOL_HASHPREFIX_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/hash/hash_append.h>
 
@@ -79,5 +78,3 @@ hash_append(Hasher& h, HashPrefix const& hp) noexcept
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/IOUAmount.h b/include/xrpl/protocol/IOUAmount.h
index 960f8c4521..52c2272da0 100644
--- a/include/xrpl/protocol/IOUAmount.h
+++ b/include/xrpl/protocol/IOUAmount.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_IOUAMOUNT_H_INCLUDED
-#define XRPL_BASICS_IOUAMOUNT_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/LocalValue.h>
 #include <xrpl/basics/Number.h>
@@ -208,5 +207,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/Indexes.h b/include/xrpl/protocol/Indexes.h
index 2ce3b7ad6b..f1e0b1655a 100644
--- a/include/xrpl/protocol/Indexes.h
+++ b/include/xrpl/protocol/Indexes.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_INDEXES_H_INCLUDED
-#define XRPL_PROTOCOL_INDEXES_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/base_uint.h>
 #include <xrpl/protocol/Book.h>
@@ -385,5 +384,3 @@ MPTID
 makeMptID(std::uint32_t sequence, AccountID const& account);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/InnerObjectFormats.h b/include/xrpl/protocol/InnerObjectFormats.h
index 6d656d0065..a00e6e120b 100644
--- a/include/xrpl/protocol/InnerObjectFormats.h
+++ b/include/xrpl/protocol/InnerObjectFormats.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_INNER_OBJECT_FORMATS_H_INCLUDED
-#define XRPL_PROTOCOL_INNER_OBJECT_FORMATS_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/KnownFormats.h>
 
@@ -24,5 +23,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/Issue.h b/include/xrpl/protocol/Issue.h
index f7da457986..c8e598a540 100644
--- a/include/xrpl/protocol/Issue.h
+++ b/include/xrpl/protocol/Issue.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_ISSUE_H_INCLUDED
-#define XRPL_PROTOCOL_ISSUE_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/json/json_value.h>
@@ -116,5 +115,3 @@ isXRP(Issue const& issue)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/KeyType.h b/include/xrpl/protocol/KeyType.h
index 454c88780d..d05e421e4b 100644
--- a/include/xrpl/protocol/KeyType.h
+++ b/include/xrpl/protocol/KeyType.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_KEYTYPE_H_INCLUDED
-#define XRPL_PROTOCOL_KEYTYPE_H_INCLUDED
+#pragma once
 
 #include <optional>
 #include <string>
@@ -43,5 +42,3 @@ operator<<(Stream& s, KeyType type)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/Keylet.h b/include/xrpl/protocol/Keylet.h
index 4380fdfdac..2931486ac0 100644
--- a/include/xrpl/protocol/Keylet.h
+++ b/include/xrpl/protocol/Keylet.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_KEYLET_H_INCLUDED
-#define XRPL_PROTOCOL_KEYLET_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/base_uint.h>
 #include <xrpl/protocol/LedgerFormats.h>
@@ -31,5 +30,3 @@ struct Keylet
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/KnownFormats.h b/include/xrpl/protocol/KnownFormats.h
index 58a2710bef..67701c91ca 100644
--- a/include/xrpl/protocol/KnownFormats.h
+++ b/include/xrpl/protocol/KnownFormats.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_KNOWNFORMATS_H_INCLUDED
-#define XRPL_PROTOCOL_KNOWNFORMATS_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/contract.h>
 #include <xrpl/beast/type_name.h>
@@ -180,5 +179,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/LedgerFormats.h b/include/xrpl/protocol/LedgerFormats.h
index b52a25af17..fa39c15843 100644
--- a/include/xrpl/protocol/LedgerFormats.h
+++ b/include/xrpl/protocol/LedgerFormats.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_LEDGERFORMATS_H_INCLUDED
-#define XRPL_PROTOCOL_LEDGERFORMATS_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/KnownFormats.h>
 
@@ -211,5 +210,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/LedgerHeader.h b/include/xrpl/protocol/LedgerHeader.h
index 641f794cdb..1dc67cada5 100644
--- a/include/xrpl/protocol/LedgerHeader.h
+++ b/include/xrpl/protocol/LedgerHeader.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_LEDGERHEADER_H_INCLUDED
-#define XRPL_PROTOCOL_LEDGERHEADER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Slice.h>
 #include <xrpl/basics/base_uint.h>
@@ -74,5 +73,3 @@ LedgerHeader
 deserializePrefixedHeader(Slice data, bool hasHash = false);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/MPTAmount.h b/include/xrpl/protocol/MPTAmount.h
index be24d4de7f..66027185b3 100644
--- a/include/xrpl/protocol/MPTAmount.h
+++ b/include/xrpl/protocol/MPTAmount.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_MPTAMOUNT_H_INCLUDED
-#define XRPL_PROTOCOL_MPTAMOUNT_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Number.h>
 #include <xrpl/basics/contract.h>
@@ -147,5 +146,3 @@ mulRatio(MPTAmount const& amt, std::uint32_t num, std::uint32_t den, bool roundU
 }
 
 }  // namespace xrpl
-
-#endif  // XRPL_BASICS_MPTAMOUNT_H_INCLUDED
diff --git a/include/xrpl/protocol/MPTIssue.h b/include/xrpl/protocol/MPTIssue.h
index ca81548a29..d84a610418 100644
--- a/include/xrpl/protocol/MPTIssue.h
+++ b/include/xrpl/protocol/MPTIssue.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_MPTISSUE_H_INCLUDED
-#define XRPL_PROTOCOL_MPTISSUE_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/AccountID.h>
 #include <xrpl/protocol/UintTypes.h>
@@ -84,5 +83,3 @@ MPTIssue
 mptIssueFromJson(Json::Value const& jv);
 
 }  // namespace xrpl
-
-#endif  // XRPL_PROTOCOL_MPTISSUE_H_INCLUDED
diff --git a/include/xrpl/protocol/MultiApiJson.h b/include/xrpl/protocol/MultiApiJson.h
index 9fdb85f648..ad7a6b8f0d 100644
--- a/include/xrpl/protocol/MultiApiJson.h
+++ b/include/xrpl/protocol/MultiApiJson.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_JSON_MULTIAPIJSON_H_INCLUDED
-#define XRPL_JSON_MULTIAPIJSON_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/json/json_value.h>
@@ -173,5 +172,3 @@ struct MultiApiJson
 using MultiApiJson = detail::MultiApiJson<RPC::apiMinimumSupportedVersion, RPC::apiMaximumValidVersion>;
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/NFTSyntheticSerializer.h b/include/xrpl/protocol/NFTSyntheticSerializer.h
index 5f7e061454..c33a6edc7d 100644
--- a/include/xrpl/protocol/NFTSyntheticSerializer.h
+++ b/include/xrpl/protocol/NFTSyntheticSerializer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_NFTSYNTHETICSERIALIZER_H_INCLUDED
-#define XRPL_PROTOCOL_NFTSYNTHETICSERIALIZER_H_INCLUDED
+#pragma once
 
 #include <xrpl/json/json_forwards.h>
 #include <xrpl/protocol/STTx.h>
@@ -22,5 +21,3 @@ insertNFTSyntheticInJson(Json::Value&, std::shared_ptr<STTx const> const&, TxMet
 
 }  // namespace RPC
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/NFTokenID.h b/include/xrpl/protocol/NFTokenID.h
index 0cddfa6d55..f3635d6fac 100644
--- a/include/xrpl/protocol/NFTokenID.h
+++ b/include/xrpl/protocol/NFTokenID.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_NFTOKENID_H_INCLUDED
-#define XRPL_PROTOCOL_NFTOKENID_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/base_uint.h>
 #include <xrpl/json/json_forwards.h>
@@ -34,5 +33,3 @@ insertNFTokenID(Json::Value& response, std::shared_ptr<STTx const> const& transa
 /** @} */
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/NFTokenOfferID.h b/include/xrpl/protocol/NFTokenOfferID.h
index da358a9b84..c3117db197 100644
--- a/include/xrpl/protocol/NFTokenOfferID.h
+++ b/include/xrpl/protocol/NFTokenOfferID.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_NFTOKENOFFERID_H_INCLUDED
-#define XRPL_PROTOCOL_NFTOKENOFFERID_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/base_uint.h>
 #include <xrpl/json/json_forwards.h>
@@ -32,5 +31,3 @@ insertNFTokenOfferID(
 /** @} */
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/PayChan.h b/include/xrpl/protocol/PayChan.h
index a991f124ff..0a1496ca8e 100644
--- a/include/xrpl/protocol/PayChan.h
+++ b/include/xrpl/protocol/PayChan.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_PAYCHAN_H_INCLUDED
-#define XRPL_PROTOCOL_PAYCHAN_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/base_uint.h>
 #include <xrpl/protocol/HashPrefix.h>
@@ -17,5 +16,3 @@ serializePayChanAuthorization(Serializer& msg, uint256 const& key, XRPAmount con
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/Permissions.h b/include/xrpl/protocol/Permissions.h
index 0e3bb970bd..e8800a41d2 100644
--- a/include/xrpl/protocol/Permissions.h
+++ b/include/xrpl/protocol/Permissions.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_PERMISSION_H_INCLUDED
-#define XRPL_PROTOCOL_PERMISSION_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/Rules.h>
 #include <xrpl/protocol/TER.h>
@@ -82,5 +81,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/Protocol.h b/include/xrpl/protocol/Protocol.h
index 99e224cb91..dfb2b9dfe8 100644
--- a/include/xrpl/protocol/Protocol.h
+++ b/include/xrpl/protocol/Protocol.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_PROTOCOL_H_INCLUDED
-#define XRPL_PROTOCOL_PROTOCOL_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/ByteUtilities.h>
 #include <xrpl/basics/base_uint.h>
@@ -298,5 +297,3 @@ std::size_t constexpr permissionMaxSize = 10;
 std::size_t constexpr maxBatchTxCount = 8;
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/PublicKey.h b/include/xrpl/protocol/PublicKey.h
index 0d95fa5818..eff2af6839 100644
--- a/include/xrpl/protocol/PublicKey.h
+++ b/include/xrpl/protocol/PublicKey.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_PUBLICKEY_H_INCLUDED
-#define XRPL_PROTOCOL_PUBLICKEY_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Slice.h>
 #include <xrpl/beast/net/IPEndpoint.h>
@@ -279,5 +278,3 @@ getOrThrow(Json::Value const& v, xrpl::SField const& field)
     Throw<JsonTypeMismatchError>(field.getJsonName(), "PublicKey");
 }
 }  // namespace Json
-
-#endif
diff --git a/include/xrpl/protocol/Quality.h b/include/xrpl/protocol/Quality.h
index d8101d7c1e..4d3fcbfcc0 100644
--- a/include/xrpl/protocol/Quality.h
+++ b/include/xrpl/protocol/Quality.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_QUALITY_H_INCLUDED
-#define XRPL_PROTOCOL_QUALITY_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/AmountConversions.h>
 #include <xrpl/protocol/IOUAmount.h>
@@ -358,5 +357,3 @@ Quality
 composed_quality(Quality const& lhs, Quality const& rhs);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/QualityFunction.h b/include/xrpl/protocol/QualityFunction.h
index 2414d86583..4f76f4df0a 100644
--- a/include/xrpl/protocol/QualityFunction.h
+++ b/include/xrpl/protocol/QualityFunction.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_QUALITYFUNCTION_H_INCLUDED
-#define XRPL_PROTOCOL_QUALITYFUNCTION_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Number.h>
 #include <xrpl/protocol/AMMCore.h>
@@ -78,5 +77,3 @@ QualityFunction::QualityFunction(TAmounts<TIn, TOut> const& amounts, std::uint32
 }
 
 }  // namespace xrpl
-
-#endif  // XRPL_PROTOCOL_QUALITYFUNCTION_H_INCLUDED
diff --git a/include/xrpl/protocol/RPCErr.h b/include/xrpl/protocol/RPCErr.h
index fcca15747e..34c4bf8f99 100644
--- a/include/xrpl/protocol/RPCErr.h
+++ b/include/xrpl/protocol/RPCErr.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NET_RPCERR_H_INCLUDED
-#define XRPL_NET_RPCERR_H_INCLUDED
+#pragma once
 
 #include <xrpl/json/json_value.h>
 
@@ -12,5 +11,3 @@ Json::Value
 rpcError(error_code_i iError);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/Rate.h b/include/xrpl/protocol/Rate.h
index 86033e9a38..e57d7e3a99 100644
--- a/include/xrpl/protocol/Rate.h
+++ b/include/xrpl/protocol/Rate.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_RATE_H_INCLUDED
-#define XRPL_PROTOCOL_RATE_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/protocol/STAmount.h>
@@ -76,5 +75,3 @@ transferFeeAsRate(std::uint16_t fee);
 extern Rate const parityRate;
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/RippleLedgerHash.h b/include/xrpl/protocol/RippleLedgerHash.h
index 516ab49029..2a51298d3d 100644
--- a/include/xrpl/protocol/RippleLedgerHash.h
+++ b/include/xrpl/protocol/RippleLedgerHash.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_RIPPLELEDGERHASH_H_INCLUDED
-#define XRPL_PROTOCOL_RIPPLELEDGERHASH_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/base_uint.h>
 
@@ -8,5 +7,3 @@ namespace xrpl {
 using LedgerHash = uint256;
 
 }
-
-#endif
diff --git a/include/xrpl/protocol/Rules.h b/include/xrpl/protocol/Rules.h
index 8f622c3f1d..7d4a458fce 100644
--- a/include/xrpl/protocol/Rules.h
+++ b/include/xrpl/protocol/Rules.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_LEDGER_RULES_H_INCLUDED
-#define XRPL_LEDGER_RULES_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/base_uint.h>
 #include <xrpl/beast/hash/uhash.h>
@@ -107,4 +106,3 @@ private:
 };
 
 }  // namespace xrpl
-#endif
diff --git a/include/xrpl/protocol/SField.h b/include/xrpl/protocol/SField.h
index 3ca8dbf898..7a864b1b58 100644
--- a/include/xrpl/protocol/SField.h
+++ b/include/xrpl/protocol/SField.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_SFIELD_H_INCLUDED
-#define XRPL_PROTOCOL_SFIELD_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/safe_cast.h>
 #include <xrpl/json/json_value.h>
@@ -374,5 +373,3 @@ extern SField const sfGeneric;
 #pragma pop_macro("UNTYPED_SFIELD")
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/SOTemplate.h b/include/xrpl/protocol/SOTemplate.h
index 35be09c5d5..794fc86c11 100644
--- a/include/xrpl/protocol/SOTemplate.h
+++ b/include/xrpl/protocol/SOTemplate.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_SOTEMPLATE_H_INCLUDED
-#define XRPL_PROTOCOL_SOTEMPLATE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/contract.h>
 #include <xrpl/protocol/SField.h>
@@ -148,5 +147,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/STAccount.h b/include/xrpl/protocol/STAccount.h
index 7c193d3425..3fdb2e015e 100644
--- a/include/xrpl/protocol/STAccount.h
+++ b/include/xrpl/protocol/STAccount.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STACCOUNT_H_INCLUDED
-#define XRPL_PROTOCOL_STACCOUNT_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/protocol/AccountID.h>
@@ -113,5 +112,3 @@ operator<(AccountID const& lhs, STAccount const& rhs)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/STAmount.h b/include/xrpl/protocol/STAmount.h
index c678205882..df2b1c19a0 100644
--- a/include/xrpl/protocol/STAmount.h
+++ b/include/xrpl/protocol/STAmount.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STAMOUNT_H_INCLUDED
-#define XRPL_PROTOCOL_STAMOUNT_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/basics/LocalValue.h>
@@ -735,4 +734,3 @@ getOrThrow(Json::Value const& v, xrpl::SField const& field)
     return amountFromJson(field, inner);
 }
 }  // namespace Json
-#endif
diff --git a/include/xrpl/protocol/STArray.h b/include/xrpl/protocol/STArray.h
index d413e7bdc0..d9c5306d14 100644
--- a/include/xrpl/protocol/STArray.h
+++ b/include/xrpl/protocol/STArray.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STARRAY_H_INCLUDED
-#define XRPL_PROTOCOL_STARRAY_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/protocol/STObject.h>
@@ -287,5 +286,3 @@ STArray::erase(const_iterator first, const_iterator last)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/STBase.h b/include/xrpl/protocol/STBase.h
index f100b52426..7f06b01ca4 100644
--- a/include/xrpl/protocol/STBase.h
+++ b/include/xrpl/protocol/STBase.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STBASE_H_INCLUDED
-#define XRPL_PROTOCOL_STBASE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/contract.h>
 #include <xrpl/protocol/SField.h>
@@ -220,5 +219,3 @@ STBase::emplace(std::size_t n, void* buf, T&& val)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/STBitString.h b/include/xrpl/protocol/STBitString.h
index 0229d99698..e8b6e7282b 100644
--- a/include/xrpl/protocol/STBitString.h
+++ b/include/xrpl/protocol/STBitString.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STBITSTRING_H_INCLUDED
-#define XRPL_PROTOCOL_STBITSTRING_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/beast/utility/Zero.h>
@@ -183,5 +182,3 @@ STBitString<Bits>::isDefault() const
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/STBlob.h b/include/xrpl/protocol/STBlob.h
index bb9b8a44f8..15a9bd5f78 100644
--- a/include/xrpl/protocol/STBlob.h
+++ b/include/xrpl/protocol/STBlob.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STBLOB_H_INCLUDED
-#define XRPL_PROTOCOL_STBLOB_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Buffer.h>
 #include <xrpl/basics/CountedObject.h>
@@ -124,5 +123,3 @@ STBlob::setValue(Buffer&& b)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/STCurrency.h b/include/xrpl/protocol/STCurrency.h
index 1c59d48beb..dc5b079c6d 100644
--- a/include/xrpl/protocol/STCurrency.h
+++ b/include/xrpl/protocol/STCurrency.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STCURRENCY_H_INCLUDED
-#define XRPL_PROTOCOL_STCURRENCY_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/protocol/SField.h>
@@ -115,5 +114,3 @@ operator<(STCurrency const& lhs, Currency const& rhs)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/STExchange.h b/include/xrpl/protocol/STExchange.h
index daf5a0e1f2..4b576991b7 100644
--- a/include/xrpl/protocol/STExchange.h
+++ b/include/xrpl/protocol/STExchange.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STEXCHANGE_H_INCLUDED
-#define XRPL_PROTOCOL_STEXCHANGE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Blob.h>
 #include <xrpl/basics/Buffer.h>
@@ -152,5 +151,3 @@ erase(STObject& st, TypedField<U> const& f)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/STInteger.h b/include/xrpl/protocol/STInteger.h
index e79f88808e..b5c4dbf6cf 100644
--- a/include/xrpl/protocol/STInteger.h
+++ b/include/xrpl/protocol/STInteger.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STINTEGER_H_INCLUDED
-#define XRPL_PROTOCOL_STINTEGER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/protocol/STBase.h>
@@ -141,5 +140,3 @@ inline STInteger<Integer>::operator Integer() const
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/STIssue.h b/include/xrpl/protocol/STIssue.h
index 404e60578c..7491e3b3ff 100644
--- a/include/xrpl/protocol/STIssue.h
+++ b/include/xrpl/protocol/STIssue.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STISSUE_H_INCLUDED
-#define XRPL_PROTOCOL_STISSUE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/protocol/Asset.h>
@@ -148,5 +147,3 @@ operator<=>(STIssue const& lhs, Asset const& rhs)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/STLedgerEntry.h b/include/xrpl/protocol/STLedgerEntry.h
index 24efab5f86..6ba3b36c6b 100644
--- a/include/xrpl/protocol/STLedgerEntry.h
+++ b/include/xrpl/protocol/STLedgerEntry.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STLEDGERENTRY_H_INCLUDED
-#define XRPL_PROTOCOL_STLEDGERENTRY_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/Indexes.h>
 #include <xrpl/protocol/STObject.h>
@@ -103,5 +102,3 @@ STLedgerEntry::getType() const
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/STNumber.h b/include/xrpl/protocol/STNumber.h
index 39b0c3b042..137016dfe7 100644
--- a/include/xrpl/protocol/STNumber.h
+++ b/include/xrpl/protocol/STNumber.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STNUMBER_H_INCLUDED
-#define XRPL_PROTOCOL_STNUMBER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/basics/Number.h>
@@ -100,5 +99,3 @@ STNumber
 numberFromJson(SField const& field, Json::Value const& value);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/STObject.h b/include/xrpl/protocol/STObject.h
index 0a2c37356a..5d5d829c99 100644
--- a/include/xrpl/protocol/STObject.h
+++ b/include/xrpl/protocol/STObject.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STOBJECT_H_INCLUDED
-#define XRPL_PROTOCOL_STOBJECT_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/basics/Slice.h>
@@ -1244,5 +1243,3 @@ STObject::peekField(SField const& field)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/STParsedJSON.h b/include/xrpl/protocol/STParsedJSON.h
index 4be10840bd..772785fd70 100644
--- a/include/xrpl/protocol/STParsedJSON.h
+++ b/include/xrpl/protocol/STParsedJSON.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STPARSEDJSON_H_INCLUDED
-#define XRPL_PROTOCOL_STPARSEDJSON_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/STArray.h>
 
@@ -36,5 +35,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/STPathSet.h b/include/xrpl/protocol/STPathSet.h
index 55e2aebe2d..1bab654d3f 100644
--- a/include/xrpl/protocol/STPathSet.h
+++ b/include/xrpl/protocol/STPathSet.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STPATHSET_H_INCLUDED
-#define XRPL_PROTOCOL_STPATHSET_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/beast/utility/instrumentation.h>
@@ -484,5 +483,3 @@ STPathSet::emplace_back(Args&&... args)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/STTakesAsset.h b/include/xrpl/protocol/STTakesAsset.h
index 767223b97d..bf75ffccf7 100644
--- a/include/xrpl/protocol/STTakesAsset.h
+++ b/include/xrpl/protocol/STTakesAsset.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STTAKESASSET_H_INCLUDED
-#define XRPL_PROTOCOL_STTAKESASSET_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/Asset.h>
 #include <xrpl/protocol/STBase.h>
@@ -59,5 +58,3 @@ void
 associateAsset(STLedgerEntry& sle, Asset const& asset);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/STTx.h b/include/xrpl/protocol/STTx.h
index f6ee91623f..a12c658dc2 100644
--- a/include/xrpl/protocol/STTx.h
+++ b/include/xrpl/protocol/STTx.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STTX_H_INCLUDED
-#define XRPL_PROTOCOL_STTX_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Expected.h>
 #include <xrpl/protocol/Feature.h>
@@ -196,5 +195,3 @@ STTx::getTransactionID() const
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/STValidation.h b/include/xrpl/protocol/STValidation.h
index 6f071acda1..aa48161f68 100644
--- a/include/xrpl/protocol/STValidation.h
+++ b/include/xrpl/protocol/STValidation.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STVALIDATION_H_INCLUDED
-#define XRPL_PROTOCOL_STVALIDATION_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/beast/utility/instrumentation.h>
@@ -245,5 +244,3 @@ STValidation::setSeen(NetClock::time_point s)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/STVector256.h b/include/xrpl/protocol/STVector256.h
index 884fd70c7c..c83d981bfc 100644
--- a/include/xrpl/protocol/STVector256.h
+++ b/include/xrpl/protocol/STVector256.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STVECTOR256_H_INCLUDED
-#define XRPL_PROTOCOL_STVECTOR256_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/protocol/STBase.h>
@@ -232,5 +231,3 @@ STVector256::clear() noexcept
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/STXChainBridge.h b/include/xrpl/protocol/STXChainBridge.h
index fdaed22594..709d3886b7 100644
--- a/include/xrpl/protocol/STXChainBridge.h
+++ b/include/xrpl/protocol/STXChainBridge.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STXCHAINBRIDGE_H_INCLUDED
-#define XRPL_PROTOCOL_STXCHAINBRIDGE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/protocol/STAccount.h>
@@ -197,5 +196,3 @@ STXChainBridge::dstChain(bool wasLockingChainSend)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/SecretKey.h b/include/xrpl/protocol/SecretKey.h
index 146e9a7105..a59b1150c1 100644
--- a/include/xrpl/protocol/SecretKey.h
+++ b/include/xrpl/protocol/SecretKey.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_SECRETKEY_H_INCLUDED
-#define XRPL_PROTOCOL_SECRETKEY_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Buffer.h>
 #include <xrpl/basics/Slice.h>
@@ -162,5 +161,3 @@ sign(KeyType type, SecretKey const& sk, Slice const& message)
 /** @} */
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/Seed.h b/include/xrpl/protocol/Seed.h
index 36b2bbfee3..1fad94e2bd 100644
--- a/include/xrpl/protocol/Seed.h
+++ b/include/xrpl/protocol/Seed.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_SEED_H_INCLUDED
-#define XRPL_PROTOCOL_SEED_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Slice.h>
 #include <xrpl/basics/base_uint.h>
@@ -118,5 +117,3 @@ toBase58(Seed const& seed)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/SeqProxy.h b/include/xrpl/protocol/SeqProxy.h
index 8dde232e75..563292f8b3 100644
--- a/include/xrpl/protocol/SeqProxy.h
+++ b/include/xrpl/protocol/SeqProxy.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_SEQ_PROXY_H_INCLUDED
-#define XRPL_PROTOCOL_SEQ_PROXY_H_INCLUDED
+#pragma once
 
 #include <cstdint>
 #include <ostream>
@@ -147,5 +146,3 @@ public:
     }
 };
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/Serializer.h b/include/xrpl/protocol/Serializer.h
index 7e294bd3a8..98cefb4d08 100644
--- a/include/xrpl/protocol/Serializer.h
+++ b/include/xrpl/protocol/Serializer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_SERIALIZER_H_INCLUDED
-#define XRPL_PROTOCOL_SERIALIZER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Blob.h>
 #include <xrpl/basics/Buffer.h>
@@ -447,5 +446,3 @@ SerialIter::getBitString()
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/Sign.h b/include/xrpl/protocol/Sign.h
index d9af89b774..9f0bf2f1ca 100644
--- a/include/xrpl/protocol/Sign.h
+++ b/include/xrpl/protocol/Sign.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_SIGN_H_INCLUDED
-#define XRPL_PROTOCOL_SIGN_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/HashPrefix.h>
 #include <xrpl/protocol/PublicKey.h>
@@ -59,5 +58,3 @@ finishMultiSigningData(AccountID const& signingID, Serializer& s)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/SystemParameters.h b/include/xrpl/protocol/SystemParameters.h
index c2f66e9ea1..70ab67c56f 100644
--- a/include/xrpl/protocol/SystemParameters.h
+++ b/include/xrpl/protocol/SystemParameters.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_SYSTEMPARAMETERS_H_INCLUDED
-#define XRPL_PROTOCOL_SYSTEMPARAMETERS_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/chrono.h>
 #include <xrpl/protocol/XRPAmount.h>
@@ -66,5 +65,3 @@ constexpr std::chrono::seconds const defaultAmendmentMajorityTime = weeks{2};
 
 /** Default peer port (IANA registered) */
 inline std::uint16_t constexpr DEFAULT_PEER_PORT{2459};
-
-#endif
diff --git a/include/xrpl/protocol/TER.h b/include/xrpl/protocol/TER.h
index 65a339231d..52001ce72b 100644
--- a/include/xrpl/protocol/TER.h
+++ b/include/xrpl/protocol/TER.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_TER_H_INCLUDED
-#define XRPL_PROTOCOL_TER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/safe_cast.h>
 #include <xrpl/json/json_value.h>
@@ -675,5 +674,3 @@ std::optional<TER>
 transCode(std::string const& token);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/TxFlags.h b/include/xrpl/protocol/TxFlags.h
index 5527a264e4..6c6ef5e369 100644
--- a/include/xrpl/protocol/TxFlags.h
+++ b/include/xrpl/protocol/TxFlags.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_TXFLAGS_H_INCLUDED
-#define XRPL_PROTOCOL_TXFLAGS_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/LedgerFormats.h>
 
@@ -295,5 +294,3 @@ constexpr std::uint32_t const tfLoanManageMask = ~(tfUniversal | tfLoanDefault |
 // clang-format on
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/TxFormats.h b/include/xrpl/protocol/TxFormats.h
index 05f03c5cdc..b76eef7585 100644
--- a/include/xrpl/protocol/TxFormats.h
+++ b/include/xrpl/protocol/TxFormats.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_TXFORMATS_H_INCLUDED
-#define XRPL_PROTOCOL_TXFORMATS_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/KnownFormats.h>
 
@@ -77,5 +76,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/TxMeta.h b/include/xrpl/protocol/TxMeta.h
index 5b6716e380..a295eb4569 100644
--- a/include/xrpl/protocol/TxMeta.h
+++ b/include/xrpl/protocol/TxMeta.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_TX_TRANSACTIONMETA_H_INCLUDED
-#define XRPL_APP_TX_TRANSACTIONMETA_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/Journal.h>
 #include <xrpl/protocol/STArray.h>
@@ -118,5 +117,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/UintTypes.h b/include/xrpl/protocol/UintTypes.h
index daa66e8286..fd48244d89 100644
--- a/include/xrpl/protocol/UintTypes.h
+++ b/include/xrpl/protocol/UintTypes.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_UINTTYPES_H_INCLUDED
-#define XRPL_PROTOCOL_UINTTYPES_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/UnorderedContainers.h>
 #include <xrpl/basics/base_uint.h>
@@ -125,5 +124,3 @@ struct hash<xrpl::uint256> : xrpl::uint256::hasher
 };
 
 }  // namespace std
-
-#endif
diff --git a/include/xrpl/protocol/Units.h b/include/xrpl/protocol/Units.h
index e52fbefe46..ecf0bf7798 100644
--- a/include/xrpl/protocol/Units.h
+++ b/include/xrpl/protocol/Units.h
@@ -1,5 +1,4 @@
-#ifndef PROTOCOL_UNITS_H_INCLUDED
-#define PROTOCOL_UNITS_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/safe_cast.h>
 #include <xrpl/beast/utility/Zero.h>
@@ -516,5 +515,3 @@ unsafe_cast(Src s) noexcept
 }
 
 }  // namespace xrpl
-
-#endif  // PROTOCOL_UNITS_H_INCLUDED
diff --git a/include/xrpl/protocol/XChainAttestations.h b/include/xrpl/protocol/XChainAttestations.h
index c5415e518b..fc3c464b92 100644
--- a/include/xrpl/protocol/XChainAttestations.h
+++ b/include/xrpl/protocol/XChainAttestations.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STXATTESTATIONS_H_INCLUDED
-#define XRPL_PROTOCOL_STXATTESTATIONS_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Buffer.h>
 #include <xrpl/basics/Expected.h>
@@ -464,5 +463,3 @@ class XChainCreateAccountAttestations final : public XChainAttestationsBase<XCha
 };
 
 }  // namespace xrpl
-
-#endif  // STXCHAINATTESTATIONS_H_
diff --git a/include/xrpl/protocol/XRPAmount.h b/include/xrpl/protocol/XRPAmount.h
index 55b9df115c..c1af338e4b 100644
--- a/include/xrpl/protocol/XRPAmount.h
+++ b/include/xrpl/protocol/XRPAmount.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_XRPAMOUNT_H_INCLUDED
-#define XRPL_PROTOCOL_XRPAMOUNT_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Number.h>
 #include <xrpl/basics/contract.h>
@@ -282,5 +281,3 @@ mulRatio(XRPAmount const& amt, std::uint32_t num, std::uint32_t den, bool roundU
 }
 
 }  // namespace xrpl
-
-#endif  // XRPL_BASICS_XRPAMOUNT_H_INCLUDED
diff --git a/include/xrpl/protocol/detail/STVar.h b/include/xrpl/protocol/detail/STVar.h
index 219d1ed738..b5373d1a4a 100644
--- a/include/xrpl/protocol/detail/STVar.h
+++ b/include/xrpl/protocol/detail/STVar.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_STVAR_H_INCLUDED
-#define XRPL_PROTOCOL_STVAR_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/SField.h>
 #include <xrpl/protocol/STBase.h>
@@ -163,5 +162,3 @@ operator!=(STVar const& lhs, STVar const& rhs)
 
 }  // namespace detail
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/detail/b58_utils.h b/include/xrpl/protocol/detail/b58_utils.h
index 1dce148aed..a34104555e 100644
--- a/include/xrpl/protocol/detail/b58_utils.h
+++ b/include/xrpl/protocol/detail/b58_utils.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_B58_UTILS_H_INCLUDED
-#define XRPL_PROTOCOL_B58_UTILS_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/contract.h>
 #include <xrpl/beast/utility/instrumentation.h>
@@ -175,4 +174,3 @@ b58_10_to_b58_be(std::uint64_t input)
 #endif
 
 }  // namespace xrpl
-#endif  // XRPL_PROTOCOL_B58_UTILS_H_INCLUDED
diff --git a/include/xrpl/protocol/detail/secp256k1.h b/include/xrpl/protocol/detail/secp256k1.h
index 0a2d5fcd8f..0ac810fd80 100644
--- a/include/xrpl/protocol/detail/secp256k1.h
+++ b/include/xrpl/protocol/detail/secp256k1.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_SECP256K1_H_INCLUDED
-#define XRPL_PROTOCOL_SECP256K1_H_INCLUDED
+#pragma once
 
 #include <secp256k1.h>
 
@@ -26,5 +25,3 @@ secp256k1Context()
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/detail/token_errors.h b/include/xrpl/protocol/detail/token_errors.h
index 1d5276e78b..686851f508 100644
--- a/include/xrpl/protocol/detail/token_errors.h
+++ b/include/xrpl/protocol/detail/token_errors.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_TOKEN_ERRORS_H_INCLUDED
-#define XRPL_PROTOCOL_TOKEN_ERRORS_H_INCLUDED
+#pragma once
 
 #include <system_error>
 
@@ -80,4 +79,3 @@ make_error_code(xrpl::TokenCodecErrc e)
     return {static_cast<int>(e), TokenCodecErrcCategory()};
 }
 }  // namespace xrpl
-#endif  // TOKEN_ERRORS_H_
diff --git a/include/xrpl/protocol/digest.h b/include/xrpl/protocol/digest.h
index bafac699f5..b5ec277e7b 100644
--- a/include/xrpl/protocol/digest.h
+++ b/include/xrpl/protocol/digest.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_DIGEST_H_INCLUDED
-#define XRPL_PROTOCOL_DIGEST_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/base_uint.h>
 #include <xrpl/crypto/secure_erase.h>
@@ -227,5 +226,3 @@ sha512Half_s(Args const&... args)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/json_get_or_throw.h b/include/xrpl/protocol/json_get_or_throw.h
index 8bc89805d3..7cdf481ad3 100644
--- a/include/xrpl/protocol/json_get_or_throw.h
+++ b/include/xrpl/protocol/json_get_or_throw.h
@@ -1,5 +1,4 @@
-#ifndef PROTOCOL_GET_OR_THROW_H_
-#define PROTOCOL_GET_OR_THROW_H_
+#pragma once
 
 #include <xrpl/basics/Buffer.h>
 #include <xrpl/basics/StringUtilities.h>
@@ -152,5 +151,3 @@ getOptional(Json::Value const& v, xrpl::SField const& field)
 }
 
 }  // namespace Json
-
-#endif  // PROTOCOL_GET_OR_THROW_H_
diff --git a/include/xrpl/protocol/jss.h b/include/xrpl/protocol/jss.h
index d86ca9bf1f..0264f625eb 100644
--- a/include/xrpl/protocol/jss.h
+++ b/include/xrpl/protocol/jss.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_JSONFIELDS_H_INCLUDED
-#define XRPL_PROTOCOL_JSONFIELDS_H_INCLUDED
+#pragma once
 
 #include <xrpl/json/json_value.h>
 
@@ -726,5 +725,3 @@ JSS(write_load);              // out: GetCounts
 
 }  // namespace jss
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/messages.h b/include/xrpl/protocol/messages.h
index d14739d532..e6654cc183 100644
--- a/include/xrpl/protocol/messages.h
+++ b/include/xrpl/protocol/messages.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_MESSAGES_H_INCLUDED
-#define XRPL_PROTOCOL_MESSAGES_H_INCLUDED
+#pragma once
 
 // Some versions of protobuf generate code that will produce errors during
 // compilation. See https://github.com/google/protobuf/issues/549 for more
@@ -13,5 +12,3 @@
 #endif
 
 #include <xrpl/proto/xrpl.pb.h>
-
-#endif
diff --git a/include/xrpl/protocol/nft.h b/include/xrpl/protocol/nft.h
index 3a8cdcd6e2..4be58c381c 100644
--- a/include/xrpl/protocol/nft.h
+++ b/include/xrpl/protocol/nft.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_NFT_H_INCLUDED
-#define XRPL_PROTOCOL_NFT_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/base_uint.h>
 #include <xrpl/basics/tagged_integer.h>
@@ -105,5 +104,3 @@ getIssuer(uint256 const& id)
 
 }  // namespace nft
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/nftPageMask.h b/include/xrpl/protocol/nftPageMask.h
index 0877d4976d..05a42ce294 100644
--- a/include/xrpl/protocol/nftPageMask.h
+++ b/include/xrpl/protocol/nftPageMask.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_NFT_PAGE_MASK_H_INCLUDED
-#define XRPL_PROTOCOL_NFT_PAGE_MASK_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/base_uint.h>
 
@@ -14,5 +13,3 @@ uint256 constexpr pageMask(std::string_view("00000000000000000000000000000000000
 
 }  // namespace nft
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/serialize.h b/include/xrpl/protocol/serialize.h
index eedf041baa..5b84a28b5d 100644
--- a/include/xrpl/protocol/serialize.h
+++ b/include/xrpl/protocol/serialize.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_SERIALIZE_H_INCLUDED
-#define XRPL_PROTOCOL_SERIALIZE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/strHex.h>
 #include <xrpl/protocol/STObject.h>
@@ -25,5 +24,3 @@ serializeHex(STObject const& o)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/protocol/st.h b/include/xrpl/protocol/st.h
index 115c373c7f..61571196f2 100644
--- a/include/xrpl/protocol/st.h
+++ b/include/xrpl/protocol/st.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_ST_H_INCLUDED
-#define XRPL_PROTOCOL_ST_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/SField.h>
 #include <xrpl/protocol/STAccount.h>
@@ -17,5 +16,3 @@
 #include <xrpl/protocol/STTx.h>
 #include <xrpl/protocol/STValidation.h>
 #include <xrpl/protocol/STVector256.h>
-
-#endif
diff --git a/include/xrpl/protocol/tokens.h b/include/xrpl/protocol/tokens.h
index 96b311a366..8cda8efc86 100644
--- a/include/xrpl/protocol/tokens.h
+++ b/include/xrpl/protocol/tokens.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PROTOCOL_TOKENS_H_INCLUDED
-#define XRPL_PROTOCOL_TOKENS_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Expected.h>
 #include <xrpl/basics/contract.h>
@@ -100,5 +99,3 @@ b58_to_b256_be(std::string_view input, std::span<std::uint8_t> out);
 }  // namespace b58_fast
 #endif  // _MSC_VER
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/resource/Charge.h b/include/xrpl/resource/Charge.h
index 1edaca28b4..55b13731b9 100644
--- a/include/xrpl/resource/Charge.h
+++ b/include/xrpl/resource/Charge.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RESOURCE_CHARGE_H_INCLUDED
-#define XRPL_RESOURCE_CHARGE_H_INCLUDED
+#pragma once
 
 #include <string>
 
@@ -50,5 +49,3 @@ operator<<(std::ostream& os, Charge const& v);
 
 }  // namespace Resource
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/resource/Consumer.h b/include/xrpl/resource/Consumer.h
index 6e973d824c..45cc221212 100644
--- a/include/xrpl/resource/Consumer.h
+++ b/include/xrpl/resource/Consumer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RESOURCE_CONSUMER_H_INCLUDED
-#define XRPL_RESOURCE_CONSUMER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/protocol/PublicKey.h>
@@ -82,5 +81,3 @@ operator<<(std::ostream& os, Consumer const& v);
 
 }  // namespace Resource
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/resource/Disposition.h b/include/xrpl/resource/Disposition.h
index 81675e8376..096afb6a6f 100644
--- a/include/xrpl/resource/Disposition.h
+++ b/include/xrpl/resource/Disposition.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RESOURCE_DISPOSITION_H_INCLUDED
-#define XRPL_RESOURCE_DISPOSITION_H_INCLUDED
+#pragma once
 
 namespace xrpl {
 namespace Resource {
@@ -20,5 +19,3 @@ enum Disposition {
 
 }  // namespace Resource
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/resource/Fees.h b/include/xrpl/resource/Fees.h
index 643a8e624c..0ba083d4fe 100644
--- a/include/xrpl/resource/Fees.h
+++ b/include/xrpl/resource/Fees.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RESOURCE_FEES_H_INCLUDED
-#define XRPL_RESOURCE_FEES_H_INCLUDED
+#pragma once
 
 #include <xrpl/resource/Charge.h>
 
@@ -41,5 +40,3 @@ extern Charge const feeDrop;              // The cost of being dropped for
 
 }  // namespace Resource
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/resource/Gossip.h b/include/xrpl/resource/Gossip.h
index dfd04288fc..e581145149 100644
--- a/include/xrpl/resource/Gossip.h
+++ b/include/xrpl/resource/Gossip.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RESOURCE_GOSSIP_H_INCLUDED
-#define XRPL_RESOURCE_GOSSIP_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/net/IPEndpoint.h>
 
@@ -27,5 +26,3 @@ struct Gossip
 
 }  // namespace Resource
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/resource/ResourceManager.h b/include/xrpl/resource/ResourceManager.h
index 4f331913ef..c04e7bb79b 100644
--- a/include/xrpl/resource/ResourceManager.h
+++ b/include/xrpl/resource/ResourceManager.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RESOURCE_MANAGER_H_INCLUDED
-#define XRPL_RESOURCE_MANAGER_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/insight/Collector.h>
 #include <xrpl/beast/net/IPEndpoint.h>
@@ -62,5 +61,3 @@ make_Manager(beast::insight::Collector::ptr const& collector, beast::Journal jou
 
 }  // namespace Resource
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/resource/Types.h b/include/xrpl/resource/Types.h
index 8923933f0f..fb71cffe37 100644
--- a/include/xrpl/resource/Types.h
+++ b/include/xrpl/resource/Types.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RESOURCE_TYPES_H_INCLUDED
-#define XRPL_RESOURCE_TYPES_H_INCLUDED
+#pragma once
 
 namespace xrpl {
 namespace Resource {
@@ -9,5 +8,3 @@ struct Entry;
 
 }  // namespace Resource
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/resource/detail/Entry.h b/include/xrpl/resource/detail/Entry.h
index 11f8a08511..ecff8828af 100644
--- a/include/xrpl/resource/detail/Entry.h
+++ b/include/xrpl/resource/detail/Entry.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RESOURCE_ENTRY_H_INCLUDED
-#define XRPL_RESOURCE_ENTRY_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/DecayingSample.h>
 #include <xrpl/beast/clock/abstract_clock.h>
@@ -90,5 +89,3 @@ operator<<(std::ostream& os, Entry const& v)
 
 }  // namespace Resource
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/resource/detail/Import.h b/include/xrpl/resource/detail/Import.h
index d33bd5f156..790fc0596a 100644
--- a/include/xrpl/resource/detail/Import.h
+++ b/include/xrpl/resource/detail/Import.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RESOURCE_IMPORT_H_INCLUDED
-#define XRPL_RESOURCE_IMPORT_H_INCLUDED
+#pragma once
 
 #include <xrpl/resource/Consumer.h>
 #include <xrpl/resource/detail/Entry.h>
@@ -32,5 +31,3 @@ struct Import
 
 }  // namespace Resource
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/resource/detail/Key.h b/include/xrpl/resource/detail/Key.h
index e63d2827ea..0c5164a7d8 100644
--- a/include/xrpl/resource/detail/Key.h
+++ b/include/xrpl/resource/detail/Key.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RESOURCE_KEY_H_INCLUDED
-#define XRPL_RESOURCE_KEY_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/net/IPEndpoint.h>
 #include <xrpl/beast/utility/instrumentation.h>
@@ -48,5 +47,3 @@ struct Key
 
 }  // namespace Resource
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/resource/detail/Kind.h b/include/xrpl/resource/detail/Kind.h
index 0e55b65780..fbb6b65e25 100644
--- a/include/xrpl/resource/detail/Kind.h
+++ b/include/xrpl/resource/detail/Kind.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RESOURCE_KIND_H_INCLUDED
-#define XRPL_RESOURCE_KIND_H_INCLUDED
+#pragma once
 
 namespace xrpl {
 namespace Resource {
@@ -16,5 +15,3 @@ enum Kind { kindInbound, kindOutbound, kindUnlimited };
 
 }  // namespace Resource
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/resource/detail/Logic.h b/include/xrpl/resource/detail/Logic.h
index e12d02b996..066e416550 100644
--- a/include/xrpl/resource/detail/Logic.h
+++ b/include/xrpl/resource/detail/Logic.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RESOURCE_LOGIC_H_INCLUDED
-#define XRPL_RESOURCE_LOGIC_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/basics/UnorderedContainers.h>
@@ -548,5 +547,3 @@ public:
 
 }  // namespace Resource
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/resource/detail/Tuning.h b/include/xrpl/resource/detail/Tuning.h
index 9d7ba31303..d5be5cf0b6 100644
--- a/include/xrpl/resource/detail/Tuning.h
+++ b/include/xrpl/resource/detail/Tuning.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RESOURCE_TUNING_H_INCLUDED
-#define XRPL_RESOURCE_TUNING_H_INCLUDED
+#pragma once
 
 #include <chrono>
 
@@ -33,5 +32,3 @@ std::chrono::seconds constexpr gossipExpirationSeconds{30};
 
 }  // namespace Resource
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/server/Handoff.h b/include/xrpl/server/Handoff.h
index 2edb6e2203..60ed16def4 100644
--- a/include/xrpl/server/Handoff.h
+++ b/include/xrpl/server/Handoff.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_HANDOFF_H_INCLUDED
-#define XRPL_SERVER_HANDOFF_H_INCLUDED
+#pragma once
 
 #include <xrpl/server/Writer.h>
 
@@ -35,5 +34,3 @@ struct Handoff
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/server/Port.h b/include/xrpl/server/Port.h
index 995401f8fd..1dfa93b0a7 100644
--- a/include/xrpl/server/Port.h
+++ b/include/xrpl/server/Port.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_PORT_H_INCLUDED
-#define XRPL_SERVER_PORT_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/BasicConfig.h>
 #include <xrpl/beast/net/IPEndpoint.h>
@@ -105,5 +104,3 @@ void
 parse_Port(ParsedPort& port, Section const& section, std::ostream& log);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/server/Server.h b/include/xrpl/server/Server.h
index 7bc7765cea..52340ac900 100644
--- a/include/xrpl/server/Server.h
+++ b/include/xrpl/server/Server.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_SERVER_H_INCLUDED
-#define XRPL_SERVER_SERVER_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/Journal.h>
 #include <xrpl/beast/utility/PropertyStream.h>
@@ -19,5 +18,3 @@ make_Server(Handler& handler, boost::asio::io_context& io_context, beast::Journa
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/server/Session.h b/include/xrpl/server/Session.h
index e2c640b827..37cbf59775 100644
--- a/include/xrpl/server/Session.h
+++ b/include/xrpl/server/Session.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_SESSION_H_INCLUDED
-#define XRPL_SERVER_SESSION_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/net/IPEndpoint.h>
 #include <xrpl/beast/utility/Journal.h>
@@ -110,5 +109,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/server/SimpleWriter.h b/include/xrpl/server/SimpleWriter.h
index 75af7169fc..87b94507a4 100644
--- a/include/xrpl/server/SimpleWriter.h
+++ b/include/xrpl/server/SimpleWriter.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_SIMPLEWRITER_H_INCLUDED
-#define XRPL_SERVER_SIMPLEWRITER_H_INCLUDED
+#pragma once
 
 #include <xrpl/server/Writer.h>
 
@@ -55,5 +54,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/server/WSSession.h b/include/xrpl/server/WSSession.h
index b2d116bb45..56105739e9 100644
--- a/include/xrpl/server/WSSession.h
+++ b/include/xrpl/server/WSSession.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_WSSESSION_H_INCLUDED
-#define XRPL_SERVER_WSSESSION_H_INCLUDED
+#pragma once
 
 #include <xrpl/server/Handoff.h>
 #include <xrpl/server/Port.h>
@@ -125,5 +124,3 @@ struct WSSession
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/server/Writer.h b/include/xrpl/server/Writer.h
index 7e0c304ea9..05fea863be 100644
--- a/include/xrpl/server/Writer.h
+++ b/include/xrpl/server/Writer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_WRITER_H_INCLUDED
-#define XRPL_SERVER_WRITER_H_INCLUDED
+#pragma once
 
 #include <boost/asio/buffer.hpp>
 
@@ -38,5 +37,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/server/detail/BaseHTTPPeer.h b/include/xrpl/server/detail/BaseHTTPPeer.h
index 2a2c523e2b..ab85cb7c89 100644
--- a/include/xrpl/server/detail/BaseHTTPPeer.h
+++ b/include/xrpl/server/detail/BaseHTTPPeer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_BASEHTTPPEER_H_INCLUDED
-#define XRPL_SERVER_BASEHTTPPEER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/beast/net/IPAddressConversion.h>
@@ -457,5 +456,3 @@ BaseHTTPPeer<Handler, Impl>::close(bool graceful)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/server/detail/BasePeer.h b/include/xrpl/server/detail/BasePeer.h
index cbd8ac2c8d..afa1ceb993 100644
--- a/include/xrpl/server/detail/BasePeer.h
+++ b/include/xrpl/server/detail/BasePeer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_BASEPEER_H_INCLUDED
-#define XRPL_SERVER_BASEPEER_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/WrappedSink.h>
 #include <xrpl/beast/utility/instrumentation.h>
@@ -88,5 +87,3 @@ BasePeer<Handler, Impl>::close()
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/server/detail/BaseWSPeer.h b/include/xrpl/server/detail/BaseWSPeer.h
index 435930e476..ab985dfac5 100644
--- a/include/xrpl/server/detail/BaseWSPeer.h
+++ b/include/xrpl/server/detail/BaseWSPeer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_BASEWSPEER_H_INCLUDED
-#define XRPL_SERVER_BASEWSPEER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/safe_cast.h>
 #include <xrpl/beast/utility/instrumentation.h>
@@ -451,5 +450,3 @@ BaseWSPeer<Handler, Impl>::fail(error_code ec, String const& what)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/server/detail/Door.h b/include/xrpl/server/detail/Door.h
index 9177d373bc..e41049f203 100644
--- a/include/xrpl/server/detail/Door.h
+++ b/include/xrpl/server/detail/Door.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_DOOR_H_INCLUDED
-#define XRPL_SERVER_DOOR_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/basics/contract.h>
@@ -424,5 +423,3 @@ Door<Handler>::should_throttle_for_fds()
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/server/detail/JSONRPCUtil.h b/include/xrpl/server/detail/JSONRPCUtil.h
index 2d4f6a6771..934085f8e6 100644
--- a/include/xrpl/server/detail/JSONRPCUtil.h
+++ b/include/xrpl/server/detail/JSONRPCUtil.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_JSONRPCUTIL_H_INCLUDED
-#define XRPL_SERVER_JSONRPCUTIL_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/Journal.h>
 #include <xrpl/json/Output.h>
@@ -11,5 +10,3 @@ void
 HTTPReply(int nStatus, std::string const& strMsg, Json::Output const&, beast::Journal j);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/server/detail/LowestLayer.h b/include/xrpl/server/detail/LowestLayer.h
index c45d948241..b8b0d46180 100644
--- a/include/xrpl/server/detail/LowestLayer.h
+++ b/include/xrpl/server/detail/LowestLayer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_LOWESTLAYER_H_INCLUDED
-#define XRPL_SERVER_LOWESTLAYER_H_INCLUDED
+#pragma once
 
 #if BOOST_VERSION >= 107000
 #include <boost/beast/core/stream_traits.hpp>
@@ -22,5 +21,3 @@ get_lowest_layer(T& t) noexcept
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/server/detail/PlainHTTPPeer.h b/include/xrpl/server/detail/PlainHTTPPeer.h
index 834a99aae8..94c84336f9 100644
--- a/include/xrpl/server/detail/PlainHTTPPeer.h
+++ b/include/xrpl/server/detail/PlainHTTPPeer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_PLAINHTTPPEER_H_INCLUDED
-#define XRPL_SERVER_PLAINHTTPPEER_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/rfc2616.h>
 #include <xrpl/server/detail/BaseHTTPPeer.h>
@@ -140,5 +139,3 @@ PlainHTTPPeer<Handler>::do_close()
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/server/detail/PlainWSPeer.h b/include/xrpl/server/detail/PlainWSPeer.h
index 4d5c57533b..9196d5ea49 100644
--- a/include/xrpl/server/detail/PlainWSPeer.h
+++ b/include/xrpl/server/detail/PlainWSPeer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_PLAINWSPEER_H_INCLUDED
-#define XRPL_SERVER_PLAINWSPEER_H_INCLUDED
+#pragma once
 
 #include <xrpl/server/detail/BaseWSPeer.h>
 
@@ -59,5 +58,3 @@ PlainWSPeer<Handler>::PlainWSPeer(
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/server/detail/SSLHTTPPeer.h b/include/xrpl/server/detail/SSLHTTPPeer.h
index b0102ac24b..138145544e 100644
--- a/include/xrpl/server/detail/SSLHTTPPeer.h
+++ b/include/xrpl/server/detail/SSLHTTPPeer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_SSLHTTPPEER_H_INCLUDED
-#define XRPL_SERVER_SSLHTTPPEER_H_INCLUDED
+#pragma once
 
 #include <xrpl/server/detail/BaseHTTPPeer.h>
 #include <xrpl/server/detail/SSLWSPeer.h>
@@ -175,5 +174,3 @@ SSLHTTPPeer<Handler>::on_shutdown(error_code ec)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/server/detail/SSLWSPeer.h b/include/xrpl/server/detail/SSLWSPeer.h
index bb5da1c6e7..b80312e55f 100644
--- a/include/xrpl/server/detail/SSLWSPeer.h
+++ b/include/xrpl/server/detail/SSLWSPeer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_SSLWSPEER_H_INCLUDED
-#define XRPL_SERVER_SSLWSPEER_H_INCLUDED
+#pragma once
 
 #include <xrpl/server/WSSession.h>
 #include <xrpl/server/detail/BaseHTTPPeer.h>
@@ -68,5 +67,3 @@ SSLWSPeer<Handler>::SSLWSPeer(
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/server/detail/ServerImpl.h b/include/xrpl/server/detail/ServerImpl.h
index e341eac849..e836b964d2 100644
--- a/include/xrpl/server/detail/ServerImpl.h
+++ b/include/xrpl/server/detail/ServerImpl.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_SERVERIMPL_H_INCLUDED
-#define XRPL_SERVER_SERVERIMPL_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/chrono.h>
 #include <xrpl/beast/core/List.h>
@@ -180,5 +179,3 @@ ServerImpl<Handler>::closed()
     return ios_.closed();
 }
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/server/detail/Spawn.h b/include/xrpl/server/detail/Spawn.h
index 1fbf9e7003..d94fb4fa05 100644
--- a/include/xrpl/server/detail/Spawn.h
+++ b/include/xrpl/server/detail/Spawn.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_SPAWN_H_INCLUDED
-#define XRPL_SERVER_SPAWN_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Log.h>
 
@@ -79,5 +78,3 @@ spawn(Ctx&& ctx, F&& func)
 }
 
 }  // namespace xrpl::util
-
-#endif
diff --git a/include/xrpl/server/detail/io_list.h b/include/xrpl/server/detail/io_list.h
index e60c33d084..5b1a02e039 100644
--- a/include/xrpl/server/detail/io_list.h
+++ b/include/xrpl/server/detail/io_list.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_IO_LIST_H_INCLUDED
-#define XRPL_SERVER_IO_LIST_H_INCLUDED
+#pragma once
 
 #include <boost/container/flat_map.hpp>
 
@@ -243,5 +242,3 @@ io_list::join()
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/shamap/Family.h b/include/xrpl/shamap/Family.h
index 6638d67df8..73887fb2dc 100644
--- a/include/xrpl/shamap/Family.h
+++ b/include/xrpl/shamap/Family.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SHAMAP_FAMILY_H_INCLUDED
-#define XRPL_SHAMAP_FAMILY_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/Journal.h>
 #include <xrpl/nodestore/Database.h>
@@ -66,5 +65,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/shamap/FullBelowCache.h b/include/xrpl/shamap/FullBelowCache.h
index 4b7a9aae67..6a6da1463a 100644
--- a/include/xrpl/shamap/FullBelowCache.h
+++ b/include/xrpl/shamap/FullBelowCache.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SHAMAP_FULLBELOWCACHE_H_INCLUDED
-#define XRPL_SHAMAP_FULLBELOWCACHE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/KeyCache.h>
 #include <xrpl/basics/TaggedCache.h>
@@ -129,5 +128,3 @@ private:
 using FullBelowCache = detail::BasicFullBelowCache;
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/shamap/SHAMap.h b/include/xrpl/shamap/SHAMap.h
index 9013b3cc9c..cd084ab48b 100644
--- a/include/xrpl/shamap/SHAMap.h
+++ b/include/xrpl/shamap/SHAMap.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SHAMAP_SHAMAP_H_INCLUDED
-#define XRPL_SHAMAP_SHAMAP_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/IntrusivePointer.h>
 #include <xrpl/basics/UnorderedContainers.h>
@@ -678,5 +677,3 @@ SHAMap::end() const
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/shamap/SHAMapAccountStateLeafNode.h b/include/xrpl/shamap/SHAMapAccountStateLeafNode.h
index c622d68a1f..552d2b4692 100644
--- a/include/xrpl/shamap/SHAMapAccountStateLeafNode.h
+++ b/include/xrpl/shamap/SHAMapAccountStateLeafNode.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SHAMAP_SHAMAPACCOUNTSTATELEAFNODE_H_INCLUDED
-#define XRPL_SHAMAP_SHAMAPACCOUNTSTATELEAFNODE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/protocol/HashPrefix.h>
@@ -60,5 +59,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/shamap/SHAMapAddNode.h b/include/xrpl/shamap/SHAMapAddNode.h
index 2dc3d15486..7d0aaf3be4 100644
--- a/include/xrpl/shamap/SHAMapAddNode.h
+++ b/include/xrpl/shamap/SHAMapAddNode.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SHAMAP_SHAMAPADDNODE_H_INCLUDED
-#define XRPL_SHAMAP_SHAMAPADDNODE_H_INCLUDED
+#pragma once
 
 #include <string>
 
@@ -161,5 +160,3 @@ SHAMapAddNode::get() const
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/shamap/SHAMapInnerNode.h b/include/xrpl/shamap/SHAMapInnerNode.h
index eab60f0348..73d59cc1fe 100644
--- a/include/xrpl/shamap/SHAMapInnerNode.h
+++ b/include/xrpl/shamap/SHAMapInnerNode.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SHAMAP_SHAMAPINNERNODE_H_INCLUDED
-#define XRPL_SHAMAP_SHAMAPINNERNODE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/IntrusivePointer.h>
 #include <xrpl/shamap/SHAMapNodeID.h>
@@ -200,4 +199,3 @@ SHAMapInnerNode::setFullBelowGen(std::uint32_t gen)
 }
 
 }  // namespace xrpl
-#endif
diff --git a/include/xrpl/shamap/SHAMapItem.h b/include/xrpl/shamap/SHAMapItem.h
index a67dfd866c..ab9cf74dc8 100644
--- a/include/xrpl/shamap/SHAMapItem.h
+++ b/include/xrpl/shamap/SHAMapItem.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SHAMAP_SHAMAPITEM_H_INCLUDED
-#define XRPL_SHAMAP_SHAMAPITEM_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/ByteUtilities.h>
 #include <xrpl/basics/CountedObject.h>
@@ -163,5 +162,3 @@ make_shamapitem(SHAMapItem const& other)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/shamap/SHAMapLeafNode.h b/include/xrpl/shamap/SHAMapLeafNode.h
index 4d18fc9108..aedcb3b79c 100644
--- a/include/xrpl/shamap/SHAMapLeafNode.h
+++ b/include/xrpl/shamap/SHAMapLeafNode.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SHAMAP_SHAMAPLEAFNODE_H_INCLUDED
-#define XRPL_SHAMAP_SHAMAPLEAFNODE_H_INCLUDED
+#pragma once
 
 #include <xrpl/shamap/SHAMapItem.h>
 #include <xrpl/shamap/SHAMapTreeNode.h>
@@ -55,5 +54,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/shamap/SHAMapMissingNode.h b/include/xrpl/shamap/SHAMapMissingNode.h
index 2b9e71dfed..f1670587eb 100644
--- a/include/xrpl/shamap/SHAMapMissingNode.h
+++ b/include/xrpl/shamap/SHAMapMissingNode.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SHAMAP_SHAMAPMISSINGNODE_H_INCLUDED
-#define XRPL_SHAMAP_SHAMAPMISSINGNODE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/base_uint.h>
 #include <xrpl/shamap/SHAMapTreeNode.h>
@@ -48,5 +47,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/shamap/SHAMapNodeID.h b/include/xrpl/shamap/SHAMapNodeID.h
index 9155b6db39..3517246f90 100644
--- a/include/xrpl/shamap/SHAMapNodeID.h
+++ b/include/xrpl/shamap/SHAMapNodeID.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SHAMAP_SHAMAPNODEID_H_INCLUDED
-#define XRPL_SHAMAP_SHAMAPNODEID_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/basics/base_uint.h>
@@ -139,5 +138,3 @@ deserializeSHAMapNodeID(std::string const& s)
 selectBranch(SHAMapNodeID const& id, uint256 const& hash);
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/shamap/SHAMapSyncFilter.h b/include/xrpl/shamap/SHAMapSyncFilter.h
index 32923c741a..219f9ac558 100644
--- a/include/xrpl/shamap/SHAMapSyncFilter.h
+++ b/include/xrpl/shamap/SHAMapSyncFilter.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SHAMAP_SHAMAPSYNCFILTER_H_INCLUDED
-#define XRPL_SHAMAP_SHAMAPSYNCFILTER_H_INCLUDED
+#pragma once
 
 #include <xrpl/shamap/SHAMapTreeNode.h>
 
@@ -27,5 +26,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/shamap/SHAMapTreeNode.h b/include/xrpl/shamap/SHAMapTreeNode.h
index 91adc8a88e..668f658754 100644
--- a/include/xrpl/shamap/SHAMapTreeNode.h
+++ b/include/xrpl/shamap/SHAMapTreeNode.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SHAMAP_SHAMAPTREENODE_H_INCLUDED
-#define XRPL_SHAMAP_SHAMAPTREENODE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/IntrusivePointer.h>
 #include <xrpl/basics/IntrusiveRefCounts.h>
@@ -168,5 +167,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/shamap/SHAMapTxLeafNode.h b/include/xrpl/shamap/SHAMapTxLeafNode.h
index 0552a86759..0a44380b9b 100644
--- a/include/xrpl/shamap/SHAMapTxLeafNode.h
+++ b/include/xrpl/shamap/SHAMapTxLeafNode.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SHAMAP_SHAMAPTXLEAFNODE_H_INCLUDED
-#define XRPL_SHAMAP_SHAMAPTXLEAFNODE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/protocol/HashPrefix.h>
@@ -58,5 +57,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/shamap/SHAMapTxPlusMetaLeafNode.h b/include/xrpl/shamap/SHAMapTxPlusMetaLeafNode.h
index 4d1dbf0a3a..d11cc87ff7 100644
--- a/include/xrpl/shamap/SHAMapTxPlusMetaLeafNode.h
+++ b/include/xrpl/shamap/SHAMapTxPlusMetaLeafNode.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SHAMAP_SHAMAPLEAFTXPLUSMETANODE_H_INCLUDED
-#define XRPL_SHAMAP_SHAMAPLEAFTXPLUSMETANODE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/protocol/HashPrefix.h>
@@ -60,5 +59,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/shamap/TreeNodeCache.h b/include/xrpl/shamap/TreeNodeCache.h
index bf9797c745..4edb6348ec 100644
--- a/include/xrpl/shamap/TreeNodeCache.h
+++ b/include/xrpl/shamap/TreeNodeCache.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SHAMAP_TREENODECACHE_H_INCLUDED
-#define XRPL_SHAMAP_TREENODECACHE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/IntrusivePointer.h>
 #include <xrpl/basics/TaggedCache.h>
@@ -14,5 +13,3 @@ using TreeNodeCache = TaggedCache<
     intr_ptr::SharedWeakUnionPtr<SHAMapTreeNode>,
     intr_ptr::SharedPtr<SHAMapTreeNode>>;
 }  // namespace xrpl
-
-#endif
diff --git a/include/xrpl/shamap/detail/TaggedPointer.h b/include/xrpl/shamap/detail/TaggedPointer.h
index e66568035b..217cd93d0a 100644
--- a/include/xrpl/shamap/detail/TaggedPointer.h
+++ b/include/xrpl/shamap/detail/TaggedPointer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SHAMAP_TAGGEDPOINTER_H_INCLUDED
-#define XRPL_SHAMAP_TAGGEDPOINTER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/IntrusivePointer.h>
 #include <xrpl/shamap/SHAMapTreeNode.h>
@@ -221,5 +220,3 @@ popcnt16(std::uint16_t a)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/csf/BasicNetwork.h b/src/test/csf/BasicNetwork.h
index 24d762deb0..697b20c2c7 100644
--- a/src/test/csf/BasicNetwork.h
+++ b/src/test/csf/BasicNetwork.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_CSF_BASICNETWORK_H_INCLUDED
-#define XRPL_TEST_CSF_BASICNETWORK_H_INCLUDED
+#pragma once
 
 #include <test/csf/Digraph.h>
 #include <test/csf/Scheduler.h>
@@ -228,5 +227,3 @@ BasicNetwork<Peer>::send(Peer const& from, Peer const& to, Function&& f)
 }  // namespace csf
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/csf/CollectorRef.h b/src/test/csf/CollectorRef.h
index 022db01008..735a42ab16 100644
--- a/src/test/csf/CollectorRef.h
+++ b/src/test/csf/CollectorRef.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_CSF_COLLECTOREF_H_INCLUDED
-#define XRPL_TEST_CSF_COLLECTOREF_H_INCLUDED
+#pragma once
 
 #include <test/csf/SimTime.h>
 #include <test/csf/events.h>
@@ -328,5 +327,3 @@ public:
 }  // namespace csf
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/csf/Digraph.h b/src/test/csf/Digraph.h
index 85baecc813..672445ca95 100644
--- a/src/test/csf/Digraph.h
+++ b/src/test/csf/Digraph.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_CSF_DIGRAPH_H_INCLUDED
-#define XRPL_TEST_CSF_DIGRAPH_H_INCLUDED
+#pragma once
 
 #include <boost/container/flat_map.hpp>
 #include <boost/range/adaptor/transformed.hpp>
@@ -228,4 +227,3 @@ public:
 }  // namespace csf
 }  // namespace test
 }  // namespace xrpl
-#endif
diff --git a/src/test/csf/Histogram.h b/src/test/csf/Histogram.h
index 61ec680939..9e7b471a2b 100644
--- a/src/test/csf/Histogram.h
+++ b/src/test/csf/Histogram.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_CSF_HISTOGRAM_H_INCLUDED
-#define XRPL_TEST_CSF_HISTOGRAM_H_INCLUDED
+#pragma once
 
 #include <algorithm>
 #include <cassert>
@@ -112,5 +111,3 @@ public:
 }  // namespace csf
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/csf/Peer.h b/src/test/csf/Peer.h
index e0bc7059a2..7b19c977d6 100644
--- a/src/test/csf/Peer.h
+++ b/src/test/csf/Peer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_CSF_PEER_H_INCLUDED
-#define XRPL_TEST_CSF_PEER_H_INCLUDED
+#pragma once
 
 #include <test/csf/CollectorRef.h>
 #include <test/csf/Scheduler.h>
@@ -937,4 +936,3 @@ struct Peer
 }  // namespace csf
 }  // namespace test
 }  // namespace xrpl
-#endif
diff --git a/src/test/csf/PeerGroup.h b/src/test/csf/PeerGroup.h
index 35a4983e4e..ce7325f659 100644
--- a/src/test/csf/PeerGroup.h
+++ b/src/test/csf/PeerGroup.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_CSF_PEERGROUP_H_INCLUDED
-#define XRPL_TEST_CSF_PEERGROUP_H_INCLUDED
+#pragma once
 
 #include <test/csf/Peer.h>
 #include <test/csf/random.h>
@@ -340,4 +339,3 @@ randomRankedConnect(
 }  // namespace csf
 }  // namespace test
 }  // namespace xrpl
-#endif
diff --git a/src/test/csf/Proposal.h b/src/test/csf/Proposal.h
index 0bcf838080..641fd2010a 100644
--- a/src/test/csf/Proposal.h
+++ b/src/test/csf/Proposal.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_CSF_PROPOSAL_H_INCLUDED
-#define XRPL_TEST_CSF_PROPOSAL_H_INCLUDED
+#pragma once
 
 #include <test/csf/Tx.h>
 #include <test/csf/Validation.h>
@@ -18,5 +17,3 @@ using Proposal = ConsensusProposal<PeerID, Ledger::ID, TxSet::ID>;
 }  // namespace csf
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/csf/Scheduler.h b/src/test/csf/Scheduler.h
index e6d53f045b..2f7535ef16 100644
--- a/src/test/csf/Scheduler.h
+++ b/src/test/csf/Scheduler.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_CSF_SCHEDULER_H_INCLUDED
-#define XRPL_TEST_CSF_SCHEDULER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/ByteUtilities.h>
 #include <xrpl/beast/clock/manual_clock.h>
@@ -428,5 +427,3 @@ Scheduler::step_for(std::chrono::duration<Period, Rep> const& amount)
 }  // namespace csf
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/csf/Sim.h b/src/test/csf/Sim.h
index ff99896e99..709226b216 100644
--- a/src/test/csf/Sim.h
+++ b/src/test/csf/Sim.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_CSF_SIM_H_INCLUDED
-#define XRPL_TEST_CSF_SIM_H_INCLUDED
+#pragma once
 
 #include <test/csf/BasicNetwork.h>
 #include <test/csf/CollectorRef.h>
@@ -148,5 +147,3 @@ public:
 }  // namespace csf
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/csf/SimTime.h b/src/test/csf/SimTime.h
index 5d8c67b8f8..2131de9b41 100644
--- a/src/test/csf/SimTime.h
+++ b/src/test/csf/SimTime.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_CSF_SIMTIME_H_INCLUDED
-#define XRPL_TEST_CSF_SIMTIME_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/clock/manual_clock.h>
 
@@ -20,5 +19,3 @@ using SimTime = typename SimClock::time_point;
 }  // namespace csf
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/csf/TrustGraph.h b/src/test/csf/TrustGraph.h
index 2eb8dac418..d25925ad38 100644
--- a/src/test/csf/TrustGraph.h
+++ b/src/test/csf/TrustGraph.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_CSF_UNL_H_INCLUDED
-#define XRPL_TEST_CSF_UNL_H_INCLUDED
+#pragma once
 
 #include <test/csf/random.h>
 
@@ -150,5 +149,3 @@ public:
 }  // namespace csf
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/csf/Tx.h b/src/test/csf/Tx.h
index 1f355829c8..20c90cbac5 100644
--- a/src/test/csf/Tx.h
+++ b/src/test/csf/Tx.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_CSF_TX_H_INCLUDED
-#define XRPL_TEST_CSF_TX_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/hash/hash_append.h>
 #include <xrpl/beast/hash/uhash.h>
@@ -207,5 +206,3 @@ hash_append(Hasher& h, Tx const& tx)
 }  // namespace csf
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/csf/Validation.h b/src/test/csf/Validation.h
index 3ec720e7d2..5ebbcf3ae5 100644
--- a/src/test/csf/Validation.h
+++ b/src/test/csf/Validation.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_CSF_VALIDATION_H_INCLUDED
-#define XRPL_TEST_CSF_VALIDATION_H_INCLUDED
+#pragma once
 
 #include <test/csf/ledgers.h>
 
@@ -176,5 +175,3 @@ public:
 }  // namespace csf
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/csf/collectors.h b/src/test/csf/collectors.h
index 5669b8a380..20fc31a01f 100644
--- a/src/test/csf/collectors.h
+++ b/src/test/csf/collectors.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_CSF_COLLECTORS_H_INCLUDED
-#define XRPL_TEST_CSF_COLLECTORS_H_INCLUDED
+#pragma once
 
 #include <test/csf/Histogram.h>
 #include <test/csf/SimTime.h>
@@ -641,5 +640,3 @@ struct JumpCollector
 }  // namespace csf
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/csf/events.h b/src/test/csf/events.h
index 29f434f4ad..2aae22d125 100644
--- a/src/test/csf/events.h
+++ b/src/test/csf/events.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_CSF_EVENTS_H_INCLUDED
-#define XRPL_TEST_CSF_EVENTS_H_INCLUDED
+#pragma once
 
 #include <test/csf/Proposal.h>
 #include <test/csf/Tx.h>
@@ -130,5 +129,3 @@ struct FullyValidateLedger
 }  // namespace csf
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/csf/ledgers.h b/src/test/csf/ledgers.h
index d28abeed4b..d78c7c29fa 100644
--- a/src/test/csf/ledgers.h
+++ b/src/test/csf/ledgers.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_CSF_LEDGERS_H_INCLUDED
-#define XRPL_TEST_CSF_LEDGERS_H_INCLUDED
+#pragma once
 
 #include <test/csf/Tx.h>
 
@@ -330,5 +329,3 @@ struct LedgerHistoryHelper
 }  // namespace csf
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/csf/random.h b/src/test/csf/random.h
index 12ff03cd64..fc5098af32 100644
--- a/src/test/csf/random.h
+++ b/src/test/csf/random.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_CSF_RANDOM_H_INCLUDED
-#define XRPL_TEST_CSF_RANDOM_H_INCLUDED
+#pragma once
 
 #include <random>
 #include <vector>
@@ -153,5 +152,3 @@ public:
 }  // namespace csf
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/csf/submitters.h b/src/test/csf/submitters.h
index fce5562014..2300b91388 100644
--- a/src/test/csf/submitters.h
+++ b/src/test/csf/submitters.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_CSF_SUBMITTERS_H_INCLUDED
-#define XRPL_TEST_CSF_SUBMITTERS_H_INCLUDED
+#pragma once
 
 #include <test/csf/Peer.h>
 #include <test/csf/Scheduler.h>
@@ -97,5 +96,3 @@ makeSubmitter(Distribution dist, SimTime start, SimTime end, Selector& sel, Sche
 }  // namespace csf
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/csf/timers.h b/src/test/csf/timers.h
index 0823dbe9b9..a071844a41 100644
--- a/src/test/csf/timers.h
+++ b/src/test/csf/timers.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_CSF_TIMERS_H_INCLUDED
-#define XRPL_TEST_CSF_TIMERS_H_INCLUDED
+#pragma once
 
 #include <test/csf/Scheduler.h>
 #include <test/csf/SimTime.h>
@@ -61,5 +60,3 @@ public:
 }  // namespace csf
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/json/TestOutputSuite.h b/src/test/json/TestOutputSuite.h
index 934fe1de81..88b7e22580 100644
--- a/src/test/json/TestOutputSuite.h
+++ b/src/test/json/TestOutputSuite.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_TESTOUTPUTSUITE_H_INCLUDED
-#define XRPL_RPC_TESTOUTPUTSUITE_H_INCLUDED
+#pragma once
 
 #include <test/jtx/TestSuite.h>
 
@@ -35,5 +34,3 @@ protected:
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx.h b/src/test/jtx.h
index 1d7f38ff54..903b029f29 100644
--- a/src/test/jtx.h
+++ b/src/test/jtx.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_H_INCLUDED
-#define XRPL_TEST_JTX_H_INCLUDED
+#pragma once
 
 // Convenience header that includes everything
 
@@ -60,5 +59,3 @@
 #include <test/jtx/utility.h>
 
 #include <xrpl/json/to_string.h>
-
-#endif
diff --git a/src/test/jtx/AMM.h b/src/test/jtx/AMM.h
index 54f5e94d03..4d8059d172 100644
--- a/src/test/jtx/AMM.h
+++ b/src/test/jtx/AMM.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_AMM_H_INCLUDED
-#define XRPL_TEST_JTX_AMM_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 #include <test/jtx/Env.h>
@@ -415,5 +414,3 @@ ammClawback(
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif  // XRPL_TEST_JTX_AMM_H_INCLUDED
diff --git a/src/test/jtx/AMMTest.h b/src/test/jtx/AMMTest.h
index f468b0ebad..be6e228c0a 100644
--- a/src/test/jtx/AMMTest.h
+++ b/src/test/jtx/AMMTest.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_AMMTEST_H_INCLUDED
-#define XRPL_TEST_JTX_AMMTEST_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 #include <test/jtx/amount.h>
@@ -159,5 +158,3 @@ protected:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif  // XRPL_TEST_JTX_AMMTEST_H_INCLUDED
diff --git a/src/test/jtx/AbstractClient.h b/src/test/jtx/AbstractClient.h
index 0bdfbd67de..9b1ef178ca 100644
--- a/src/test/jtx/AbstractClient.h
+++ b/src/test/jtx/AbstractClient.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_ABSTRACTCLIENT_H_INCLUDED
-#define XRPL_TEST_ABSTRACTCLIENT_H_INCLUDED
+#pragma once
 
 #include <xrpl/json/json_value.h>
 
@@ -41,5 +40,3 @@ public:
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/Account.h b/src/test/jtx/Account.h
index 2f35d71a5c..6f796e08b3 100644
--- a/src/test/jtx/Account.h
+++ b/src/test/jtx/Account.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_ACCOUNT_H_INCLUDED
-#define XRPL_TEST_JTX_ACCOUNT_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/hash/uhash.h>
 #include <xrpl/protocol/KeyType.h>
@@ -147,5 +146,3 @@ operator<=>(Account const& lhs, Account const& rhs) noexcept
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/CaptureLogs.h b/src/test/jtx/CaptureLogs.h
index 89f207a2fc..f8d0449977 100644
--- a/src/test/jtx/CaptureLogs.h
+++ b/src/test/jtx/CaptureLogs.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_CAPTURELOGS_H_INCLUDED
-#define XRPL_TEST_JTX_CAPTURELOGS_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Log.h>
 
@@ -66,5 +65,3 @@ public:
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/CheckMessageLogs.h b/src/test/jtx/CheckMessageLogs.h
index 83aa73a337..286cfa1844 100644
--- a/src/test/jtx/CheckMessageLogs.h
+++ b/src/test/jtx/CheckMessageLogs.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_CHECKMESSAGELOGS_H_INCLUDED
-#define XRPL_TEST_JTX_CHECKMESSAGELOGS_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Log.h>
 
@@ -58,5 +57,3 @@ public:
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/Env.h b/src/test/jtx/Env.h
index 1c07ac2d00..ef6240d48a 100644
--- a/src/test/jtx/Env.h
+++ b/src/test/jtx/Env.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_ENV_H_INCLUDED
-#define XRPL_TEST_JTX_ENV_H_INCLUDED
+#pragma once
 
 #include <test/jtx/AbstractClient.h>
 #include <test/jtx/Account.h>
@@ -779,5 +778,3 @@ Env::rpc(std::string const& cmd, Args&&... args)
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/Env_ss.h b/src/test/jtx/Env_ss.h
index 734eca5819..78146a04a4 100644
--- a/src/test/jtx/Env_ss.h
+++ b/src/test/jtx/Env_ss.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_ENV_SS_H_INCLUDED
-#define XRPL_TEST_JTX_ENV_SS_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -60,5 +59,3 @@ public:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/JSONRPCClient.h b/src/test/jtx/JSONRPCClient.h
index 0513b43a93..41129a36ec 100644
--- a/src/test/jtx/JSONRPCClient.h
+++ b/src/test/jtx/JSONRPCClient.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_HTTPCLIENT_H_INCLUDED
-#define XRPL_TEST_HTTPCLIENT_H_INCLUDED
+#pragma once
 
 #include <test/jtx/AbstractClient.h>
 
@@ -16,5 +15,3 @@ makeJSONRPCClient(Config const& cfg, unsigned rpc_version = 2);
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/JTx.h b/src/test/jtx/JTx.h
index 1568df5f18..90fbb8a6b6 100644
--- a/src/test/jtx/JTx.h
+++ b/src/test/jtx/JTx.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_JTX_H_INCLUDED
-#define XRPL_TEST_JTX_JTX_H_INCLUDED
+#pragma once
 
 #include <test/jtx/basic_prop.h>
 #include <test/jtx/requires.h>
@@ -159,5 +158,3 @@ private:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/ManualTimeKeeper.h b/src/test/jtx/ManualTimeKeeper.h
index df3c7ff89a..d5fdd467e1 100644
--- a/src/test/jtx/ManualTimeKeeper.h
+++ b/src/test/jtx/ManualTimeKeeper.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_MANUALTIMEKEEPER_H_INCLUDED
-#define XRPL_TEST_MANUALTIMEKEEPER_H_INCLUDED
+#pragma once
 
 #include <xrpld/core/TimeKeeper.h>
 
@@ -31,5 +30,3 @@ public:
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/Oracle.h b/src/test/jtx/Oracle.h
index 6d993c436e..da241c0ce8 100644
--- a/src/test/jtx/Oracle.h
+++ b/src/test/jtx/Oracle.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_ORACLE_H_INCLUDED
-#define XRPL_TEST_JTX_ORACLE_H_INCLUDED
+#pragma once
 
 #include <test/jtx.h>
 
@@ -181,5 +180,3 @@ public:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif  // XRPL_TEST_JTX_ORACLE_H_INCLUDED
diff --git a/src/test/jtx/PathSet.h b/src/test/jtx/PathSet.h
index fe96a9884a..3f30d7193f 100644
--- a/src/test/jtx/PathSet.h
+++ b/src/test/jtx/PathSet.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_LEDGER_TESTS_PATHSET_H_INCLUDED
-#define XRPL_LEDGER_TESTS_PATHSET_H_INCLUDED
+#pragma once
 
 #include <test/jtx.h>
 
@@ -159,5 +158,3 @@ private:
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/SignerUtils.h b/src/test/jtx/SignerUtils.h
index 4c0218f6b4..37b1d85ec7 100644
--- a/src/test/jtx/SignerUtils.h
+++ b/src/test/jtx/SignerUtils.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_SIGNERUTILS_H_INCLUDED
-#define XRPL_TEST_JTX_SIGNERUTILS_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 
@@ -47,5 +46,3 @@ sortSigners(std::vector<Reg>& signers)
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/TestHelpers.h b/src/test/jtx/TestHelpers.h
index ccf270867c..aea9edeb93 100644
--- a/src/test/jtx/TestHelpers.h
+++ b/src/test/jtx/TestHelpers.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_TESTHELPERS_H_INCLUDED
-#define XRPL_TEST_JTX_TESTHELPERS_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -735,5 +734,3 @@ pay(AccountID const& account, uint256 const& loanID, STAmount const& amount, std
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif  // XRPL_TEST_JTX_TESTHELPERS_H_INCLUDED
diff --git a/src/test/jtx/TestSuite.h b/src/test/jtx/TestSuite.h
index e54bc7d131..1558f68d39 100644
--- a/src/test/jtx/TestSuite.h
+++ b/src/test/jtx/TestSuite.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_TESTSUITE_H_INCLUDED
-#define XRPL_BASICS_TESTSUITE_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/unit_test.h>
 
@@ -112,5 +111,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/TrustedPublisherServer.h b/src/test/jtx/TrustedPublisherServer.h
index 2d5b98417b..a46e98ad50 100644
--- a/src/test/jtx/TrustedPublisherServer.h
+++ b/src/test/jtx/TrustedPublisherServer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_TRUSTED_PUBLISHER_SERVER_H_INCLUDED
-#define XRPL_TEST_TRUSTED_PUBLISHER_SERVER_H_INCLUDED
+#pragma once
 
 #include <test/jtx/envconfig.h>
 
@@ -647,4 +646,3 @@ make_TrustedPublisherServer(
 
 }  // namespace test
 }  // namespace xrpl
-#endif
diff --git a/src/test/jtx/WSClient.h b/src/test/jtx/WSClient.h
index 9e9fb60bfc..86b81ac0ac 100644
--- a/src/test/jtx/WSClient.h
+++ b/src/test/jtx/WSClient.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_WSCLIENT_H_INCLUDED
-#define XRPL_TEST_WSCLIENT_H_INCLUDED
+#pragma once
 
 #include <test/jtx/AbstractClient.h>
 
@@ -34,5 +33,3 @@ makeWSClient(
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/account_txn_id.h b/src/test/jtx/account_txn_id.h
index fb48941925..71ac606418 100644
--- a/src/test/jtx/account_txn_id.h
+++ b/src/test/jtx/account_txn_id.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_ACCOUNT_TXN_ID_H_INCLUDED
-#define XRPL_TEST_JTX_ACCOUNT_TXN_ID_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -23,4 +22,3 @@ public:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-#endif
diff --git a/src/test/jtx/acctdelete.h b/src/test/jtx/acctdelete.h
index f5d1f7d869..c081eb92a5 100644
--- a/src/test/jtx/acctdelete.h
+++ b/src/test/jtx/acctdelete.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_ACCTDELETE_H_INCLUDED
-#define XRPL_TEST_JTX_ACCTDELETE_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 #include <test/jtx/Env.h>
@@ -24,5 +23,3 @@ incLgrSeqForAccDel(jtx::Env& env, jtx::Account const& acc, std::uint32_t margin
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/amount.h b/src/test/jtx/amount.h
index 958160224d..c7b66504d3 100644
--- a/src/test/jtx/amount.h
+++ b/src/test/jtx/amount.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_AMOUNT_H_INCLUDED
-#define XRPL_TEST_JTX_AMOUNT_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 #include <test/jtx/tags.h>
@@ -588,5 +587,3 @@ extern any_t const any;
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/attester.h b/src/test/jtx/attester.h
index 345002f90a..6904135f21 100644
--- a/src/test/jtx/attester.h
+++ b/src/test/jtx/attester.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_ATTESTER_H_INCLUDED
-#define XRPL_TEST_JTX_ATTESTER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Buffer.h>
 #include <xrpl/protocol/AccountID.h>
@@ -44,5 +43,3 @@ sign_create_account_attestation(
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/balance.h b/src/test/jtx/balance.h
index 741bbcb195..83e2e3ea03 100644
--- a/src/test/jtx/balance.h
+++ b/src/test/jtx/balance.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_BALANCE_H_INCLUDED
-#define XRPL_TEST_JTX_BALANCE_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 #include <test/jtx/tags.h>
@@ -43,5 +42,3 @@ public:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/basic_prop.h b/src/test/jtx/basic_prop.h
index 32655e9f52..080eecd34b 100644
--- a/src/test/jtx/basic_prop.h
+++ b/src/test/jtx/basic_prop.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_BASIC_PROP_H_INCLUDED
-#define XRPL_TEST_JTX_BASIC_PROP_H_INCLUDED
+#pragma once
 
 #include <memory>
 
@@ -42,5 +41,3 @@ struct prop_type : basic_prop
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/batch.h b/src/test/jtx/batch.h
index 51ded4ee1b..c11a9fe17e 100644
--- a/src/test/jtx/batch.h
+++ b/src/test/jtx/batch.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_BATCH_H_INCLUDED
-#define XRPL_TEST_JTX_BATCH_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 #include <test/jtx/Env.h>
@@ -133,5 +132,3 @@ public:
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/check.h b/src/test/jtx/check.h
index 61ae5033e4..9a1c6b2d2c 100644
--- a/src/test/jtx/check.h
+++ b/src/test/jtx/check.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_CHECK_H_INCLUDED
-#define XRPL_TEST_JTX_CHECK_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 #include <test/jtx/Env.h>
@@ -42,5 +41,3 @@ using checks = owner_count<ltCHECK>;
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/credentials.h b/src/test/jtx/credentials.h
index 96b3fcf103..29ecacb11b 100644
--- a/src/test/jtx/credentials.h
+++ b/src/test/jtx/credentials.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_CREDENTIALS_H_INCLUDED
-#define XRPL_TEST_JTX_CREDENTIALS_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 #include <test/jtx/Env.h>
@@ -74,5 +73,3 @@ ledgerEntry(jtx::Env& env, std::string const& credIdx);
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/delivermin.h b/src/test/jtx/delivermin.h
index 033b3f20b8..3edb38ffef 100644
--- a/src/test/jtx/delivermin.h
+++ b/src/test/jtx/delivermin.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_DELIVERMIN_H_INCLUDED
-#define XRPL_TEST_JTX_DELIVERMIN_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -27,5 +26,3 @@ public:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/deposit.h b/src/test/jtx/deposit.h
index 579a7bafb9..d7762e9ae3 100644
--- a/src/test/jtx/deposit.h
+++ b/src/test/jtx/deposit.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_DEPOSIT_H_INCLUDED
-#define XRPL_TEST_JTX_DEPOSIT_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 #include <test/jtx/Env.h>
@@ -59,5 +58,3 @@ unauthCredentials(jtx::Account const& account, std::vector<AuthorizeCredentials>
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/did.h b/src/test/jtx/did.h
index 65407028eb..9cd98a1324 100644
--- a/src/test/jtx/did.h
+++ b/src/test/jtx/did.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_DID_H_INCLUDED
-#define XRPL_TEST_JTX_DID_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 #include <test/jtx/Env.h>
@@ -81,5 +80,3 @@ del(jtx::Account const& account);
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/directory.h b/src/test/jtx/directory.h
index 25ec202cec..e9fff35434 100644
--- a/src/test/jtx/directory.h
+++ b/src/test/jtx/directory.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_DIRECTORY_H_INCLUDED
-#define XRPL_TEST_JTX_DIRECTORY_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -57,5 +56,3 @@ maximumPageIndex(Env const& env) -> std::uint64_t
 }  // namespace directory
 
 }  // namespace xrpl::test::jtx
-
-#endif
diff --git a/src/test/jtx/envconfig.h b/src/test/jtx/envconfig.h
index 9cf5cff146..dc0c48e064 100644
--- a/src/test/jtx/envconfig.h
+++ b/src/test/jtx/envconfig.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_ENVCONFIG_H_INCLUDED
-#define XRPL_TEST_JTX_ENVCONFIG_H_INCLUDED
+#pragma once
 
 #include <xrpld/core/Config.h>
 
@@ -112,5 +111,3 @@ makeConfig(std::map<std::string, std::string> extraTxQ = {}, std::map<std::strin
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/escrow.h b/src/test/jtx/escrow.h
index 1bfe170802..c3f535e29f 100644
--- a/src/test/jtx/escrow.h
+++ b/src/test/jtx/escrow.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_ESCROW_H_INCLUDED
-#define XRPL_TEST_JTX_ESCROW_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 #include <test/jtx/Env.h>
@@ -86,5 +85,3 @@ auto const fulfillment = JTxFieldWrapper<blobField>(sfFulfillment);
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/fee.h b/src/test/jtx/fee.h
index 3ede9680f8..281066f0aa 100644
--- a/src/test/jtx/fee.h
+++ b/src/test/jtx/fee.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_FEE_H_INCLUDED
-#define XRPL_TEST_JTX_FEE_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 #include <test/jtx/tags.h>
@@ -51,5 +50,3 @@ public:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/flags.h b/src/test/jtx/flags.h
index 3f1f8f71a3..3dde1fa414 100644
--- a/src/test/jtx/flags.h
+++ b/src/test/jtx/flags.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_FLAGS_H_INCLUDED
-#define XRPL_TEST_JTX_FLAGS_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -139,5 +138,3 @@ public:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/invoice_id.h b/src/test/jtx/invoice_id.h
index bdf1aa4250..fd1b7ae45b 100644
--- a/src/test/jtx/invoice_id.h
+++ b/src/test/jtx/invoice_id.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_INVOICE_ID_H_INCLUDED
-#define XRPL_TEST_JTX_INVOICE_ID_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -23,4 +22,3 @@ public:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-#endif
diff --git a/src/test/jtx/jtx_json.h b/src/test/jtx/jtx_json.h
index 32fd3c8d30..c7f52fe283 100644
--- a/src/test/jtx/jtx_json.h
+++ b/src/test/jtx/jtx_json.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_JSON_H_INCLUDED
-#define XRPL_TEST_JTX_JSON_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -41,5 +40,3 @@ public:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/last_ledger_sequence.h b/src/test/jtx/last_ledger_sequence.h
index 6544294bd6..540d6ff384 100644
--- a/src/test/jtx/last_ledger_sequence.h
+++ b/src/test/jtx/last_ledger_sequence.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_LAST_LEDGER_SEQUENCE_H_INCLUDED
-#define XRPL_TEST_JTX_LAST_LEDGER_SEQUENCE_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -24,5 +23,3 @@ public:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/ledgerStateFix.h b/src/test/jtx/ledgerStateFix.h
index f93c1bc3d8..7adc863cb4 100644
--- a/src/test/jtx/ledgerStateFix.h
+++ b/src/test/jtx/ledgerStateFix.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_LEDGER_STATE_FIX_H_INCLUDED
-#define XRPL_TEST_JTX_LEDGER_STATE_FIX_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 #include <test/jtx/Env.h>
@@ -21,5 +20,3 @@ nftPageLinks(jtx::Account const& acct, jtx::Account const& owner);
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/memo.h b/src/test/jtx/memo.h
index c0f8ae5f27..2371490b30 100644
--- a/src/test/jtx/memo.h
+++ b/src/test/jtx/memo.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_MEMO_H_INCLUDED
-#define XRPL_TEST_JTX_MEMO_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -74,5 +73,3 @@ public:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/mpt.h b/src/test/jtx/mpt.h
index fc66b50a1e..792d43056f 100644
--- a/src/test/jtx/mpt.h
+++ b/src/test/jtx/mpt.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_MPT_H_INCLUDED
-#define XRPL_TEST_JTX_MPT_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 #include <test/jtx/Env.h>
@@ -299,5 +298,3 @@ private:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/multisign.h b/src/test/jtx/multisign.h
index f1a50728b9..3bbf43bb05 100644
--- a/src/test/jtx/multisign.h
+++ b/src/test/jtx/multisign.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_MULTISIGN_H_INCLUDED
-#define XRPL_TEST_JTX_MULTISIGN_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 #include <test/jtx/SignerUtils.h>
@@ -97,5 +96,3 @@ using siglists = owner_count<ltSIGNER_LIST>;
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/noop.h b/src/test/jtx/noop.h
index 3ef3a57c4b..47d12fb9af 100644
--- a/src/test/jtx/noop.h
+++ b/src/test/jtx/noop.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_NOOP_H_INCLUDED
-#define XRPL_TEST_JTX_NOOP_H_INCLUDED
+#pragma once
 
 #include <test/jtx/flags.h>
 
@@ -17,5 +16,3 @@ noop(Account const& account)
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/offer.h b/src/test/jtx/offer.h
index 22bc14a09d..dab15a4c8c 100644
--- a/src/test/jtx/offer.h
+++ b/src/test/jtx/offer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_OFFER_H_INCLUDED
-#define XRPL_TEST_JTX_OFFER_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 
@@ -21,5 +20,3 @@ offer_cancel(Account const& account, std::uint32_t offerSeq);
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/owners.h b/src/test/jtx/owners.h
index 73a244185f..87fa26417a 100644
--- a/src/test/jtx/owners.h
+++ b/src/test/jtx/owners.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_OWNERS_H_INCLUDED
-#define XRPL_TEST_JTX_OWNERS_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -69,5 +68,3 @@ using offers = owner_count<ltOFFER>;
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/paths.h b/src/test/jtx/paths.h
index a1e5ee0294..c4e69fe3f3 100644
--- a/src/test/jtx/paths.h
+++ b/src/test/jtx/paths.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_PATHS_H_INCLUDED
-#define XRPL_TEST_JTX_PATHS_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -94,5 +93,3 @@ path::append(T const& t, Args const&... args)
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/pay.h b/src/test/jtx/pay.h
index 4ef13d72a3..a155d7bdc8 100644
--- a/src/test/jtx/pay.h
+++ b/src/test/jtx/pay.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_PAY_H_INCLUDED
-#define XRPL_TEST_JTX_PAY_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 #include <test/jtx/amount.h>
@@ -19,5 +18,3 @@ pay(Account const& account, Account const& to, AnyAmount amount);
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/permissioned_domains.h b/src/test/jtx/permissioned_domains.h
index de015775ce..ff8ab129ae 100644
--- a/src/test/jtx/permissioned_domains.h
+++ b/src/test/jtx/permissioned_domains.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_PERMISSIONED_DOMAINS_H_INCLUDED
-#define XRPL_TEST_JTX_PERMISSIONED_DOMAINS_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 #include <test/jtx/Env.h>
@@ -47,5 +46,3 @@ getNewDomain(std::shared_ptr<STObject const> const& meta);
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/prop.h b/src/test/jtx/prop.h
index 5c4687f88b..b1f8cb5ffc 100644
--- a/src/test/jtx/prop.h
+++ b/src/test/jtx/prop.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_PROP_H_INCLUDED
-#define XRPL_TEST_JTX_PROP_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -30,5 +29,3 @@ struct prop
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/quality.h b/src/test/jtx/quality.h
index c112ad9934..34c960224f 100644
--- a/src/test/jtx/quality.h
+++ b/src/test/jtx/quality.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_QUALITY_H_INCLUDED
-#define XRPL_TEST_JTX_QUALITY_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -66,5 +65,3 @@ public:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/rate.h b/src/test/jtx/rate.h
index 2ed8cec6f2..a92bd2364a 100644
--- a/src/test/jtx/rate.h
+++ b/src/test/jtx/rate.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_RATE_H_INCLUDED
-#define XRPL_TEST_JTX_RATE_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 
@@ -16,5 +15,3 @@ rate(Account const& account, double multiplier);
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/regkey.h b/src/test/jtx/regkey.h
index b3ab9a0ed9..2c95baacc3 100644
--- a/src/test/jtx/regkey.h
+++ b/src/test/jtx/regkey.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_REGKEY_H_INCLUDED
-#define XRPL_TEST_JTX_REGKEY_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 #include <test/jtx/tags.h>
@@ -21,5 +20,3 @@ regkey(Account const& account, Account const& signer);
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/require.h b/src/test/jtx/require.h
index 21ff8a29ec..7d712e8ab7 100644
--- a/src/test/jtx/require.h
+++ b/src/test/jtx/require.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_REQUIRE_H_INCLUDED
-#define XRPL_TEST_JTX_REQUIRE_H_INCLUDED
+#pragma once
 
 #include <test/jtx/requires.h>
 
@@ -64,5 +63,3 @@ public:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/requires.h b/src/test/jtx/requires.h
index 379c5ad67d..2411d040c6 100644
--- a/src/test/jtx/requires.h
+++ b/src/test/jtx/requires.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_REQUIRES_H_INCLUDED
-#define XRPL_TEST_JTX_REQUIRES_H_INCLUDED
+#pragma once
 
 #include <functional>
 #include <vector>
@@ -16,5 +15,3 @@ using requires_t = std::vector<require_t>;
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/rpc.h b/src/test/jtx/rpc.h
index 30b4f4b1fd..6946cbc4e1 100644
--- a/src/test/jtx/rpc.h
+++ b/src/test/jtx/rpc.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_RPC_H_INCLUDED
-#define XRPL_TEST_JTX_RPC_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -59,5 +58,3 @@ public:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/sendmax.h b/src/test/jtx/sendmax.h
index 9082ef9ddd..8a471be3cd 100644
--- a/src/test/jtx/sendmax.h
+++ b/src/test/jtx/sendmax.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_SENDMAX_H_INCLUDED
-#define XRPL_TEST_JTX_SENDMAX_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -27,5 +26,3 @@ public:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/seq.h b/src/test/jtx/seq.h
index 102961db0e..b861800ac9 100644
--- a/src/test/jtx/seq.h
+++ b/src/test/jtx/seq.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_SEQ_H_INCLUDED
-#define XRPL_TEST_JTX_SEQ_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 #include <test/jtx/tags.h>
@@ -37,5 +36,3 @@ public:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/sig.h b/src/test/jtx/sig.h
index 1397e5fc71..ab22a46c69 100644
--- a/src/test/jtx/sig.h
+++ b/src/test/jtx/sig.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_SIG_H_INCLUDED
-#define XRPL_TEST_JTX_SIG_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -59,5 +58,3 @@ public:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/tag.h b/src/test/jtx/tag.h
index 688d2e92c1..c8d5723754 100644
--- a/src/test/jtx/tag.h
+++ b/src/test/jtx/tag.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_TAG_H_INCLUDED
-#define XRPL_TEST_JTX_TAG_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -42,5 +41,3 @@ public:
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/tags.h b/src/test/jtx/tags.h
index 445bdebcb4..c8a6170048 100644
--- a/src/test/jtx/tags.h
+++ b/src/test/jtx/tags.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_TAGS_H_INCLUDED
-#define XRPL_TEST_JTX_TAGS_H_INCLUDED
+#pragma once
 
 namespace xrpl {
 namespace test {
@@ -44,5 +43,3 @@ static increment_t const increment;
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/ter.h b/src/test/jtx/ter.h
index f13c2a90e6..074ba307cb 100644
--- a/src/test/jtx/ter.h
+++ b/src/test/jtx/ter.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_TER_H_INCLUDED
-#define XRPL_TEST_JTX_TER_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -36,5 +35,3 @@ public:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/testline.h b/src/test/jtx/testline.h
index beda870345..e2be1f0276 100644
--- a/src/test/jtx/testline.h
+++ b/src/test/jtx/testline.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_TESTLINE_H_INCLUDED
-#define XRPL_TEST_JTX_TESTLINE_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -30,5 +29,3 @@ public:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/ticket.h b/src/test/jtx/ticket.h
index 10cb772bbd..dca16ac7c6 100644
--- a/src/test/jtx/ticket.h
+++ b/src/test/jtx/ticket.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_TICKET_H_INCLUDED
-#define XRPL_TEST_JTX_TICKET_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 #include <test/jtx/Env.h>
@@ -48,5 +47,3 @@ using tickets = owner_count<ltTICKET>;
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/token.h b/src/test/jtx/token.h
index 2c9ecc8393..f6d562587a 100644
--- a/src/test/jtx/token.h
+++ b/src/test/jtx/token.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_NFT_H_INCLUDED
-#define XRPL_TEST_JTX_NFT_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 #include <test/jtx/Env.h>
@@ -218,5 +217,3 @@ modify(jtx::Account const& account, uint256 const& nftokenID);
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif  // XRPL_TEST_JTX_NFT_H_INCLUDED
diff --git a/src/test/jtx/trust.h b/src/test/jtx/trust.h
index 34eba0a63b..462538854b 100644
--- a/src/test/jtx/trust.h
+++ b/src/test/jtx/trust.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_TRUST_H_INCLUDED
-#define XRPL_TEST_JTX_TRUST_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 
@@ -24,5 +23,3 @@ claw(Account const& account, STAmount const& amount, std::optional<Account> cons
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/txflags.h b/src/test/jtx/txflags.h
index 75a0d2740b..f51c26d035 100644
--- a/src/test/jtx/txflags.h
+++ b/src/test/jtx/txflags.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_TXFLAGS_H_INCLUDED
-#define XRPL_TEST_JTX_TXFLAGS_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Env.h>
 
@@ -25,5 +24,3 @@ public:
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/utility.h b/src/test/jtx/utility.h
index b28868af65..895d00f12b 100644
--- a/src/test/jtx/utility.h
+++ b/src/test/jtx/utility.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_UTILITY_H_INCLUDED
-#define XRPL_TEST_JTX_UTILITY_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 
@@ -58,5 +57,3 @@ cmdToJSONRPC(std::vector<std::string> const& args, beast::Journal j, unsigned in
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/vault.h b/src/test/jtx/vault.h
index 485940f9f4..65a5706354 100644
--- a/src/test/jtx/vault.h
+++ b/src/test/jtx/vault.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_VAULT_H_INCLUDED
-#define XRPL_TEST_JTX_VAULT_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 #include <test/jtx/amount.h>
@@ -86,5 +85,3 @@ struct Vault
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/jtx/xchain_bridge.h b/src/test/jtx/xchain_bridge.h
index f7c1f019c9..cdacede234 100644
--- a/src/test/jtx/xchain_bridge.h
+++ b/src/test/jtx/xchain_bridge.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TEST_JTX_XCHAINBRIDGE_H_INCLUDED
-#define XRPL_TEST_JTX_XCHAINBRIDGE_H_INCLUDED
+#pragma once
 
 #include <test/jtx/Account.h>
 #include <test/jtx/amount.h>
@@ -219,5 +218,3 @@ struct XChainBridgeObjects
 }  // namespace jtx
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/nodestore/TestBase.h b/src/test/nodestore/TestBase.h
index c08559de36..dfa2b05642 100644
--- a/src/test/nodestore/TestBase.h
+++ b/src/test/nodestore/TestBase.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NODESTORE_BASE_H_INCLUDED
-#define XRPL_NODESTORE_BASE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/StringUtilities.h>
 #include <xrpl/basics/random.h>
@@ -197,5 +196,3 @@ public:
 
 }  // namespace NodeStore
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/protocol/Issue_test.cpp b/src/test/protocol/Issue_test.cpp
index 661a8c912b..2321da4a6e 100644
--- a/src/test/protocol/Issue_test.cpp
+++ b/src/test/protocol/Issue_test.cpp
@@ -17,14 +17,6 @@
 #define STL_SET_HAS_EMPLACE 0
 #endif
 
-#ifndef XRPL_ASSETS_ENABLE_STD_HASH
-#if BEAST_MAC || BEAST_IOS
-#define XRPL_ASSETS_ENABLE_STD_HASH 0
-#else
-#define XRPL_ASSETS_ENABLE_STD_HASH 1
-#endif
-#endif
-
 namespace xrpl {
 
 class Issue_test : public beast::unit_test::suite
diff --git a/src/test/rpc/GRPCTestClientBase.h b/src/test/rpc/GRPCTestClientBase.h
index 5e547b1dfb..3c39cd1747 100644
--- a/src/test/rpc/GRPCTestClientBase.h
+++ b/src/test/rpc/GRPCTestClientBase.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_GRPCTESTCLIENTBASE_H
-#define XRPL_GRPCTESTCLIENTBASE_H
+#pragma once
 
 #include <test/jtx/envconfig.h>
 
@@ -26,4 +25,3 @@ struct GRPCTestClientBase
 
 }  // namespace test
 }  // namespace xrpl
-#endif  // XRPL_GRPCTESTCLIENTBASE_H
diff --git a/src/test/shamap/common.h b/src/test/shamap/common.h
index 1779755619..fe2a1884da 100644
--- a/src/test/shamap/common.h
+++ b/src/test/shamap/common.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SHAMAP_TESTS_COMMON_H_INCLUDED
-#define XRPL_SHAMAP_TESTS_COMMON_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/chrono.h>
 #include <xrpl/nodestore/DummyScheduler.h>
@@ -100,5 +99,3 @@ public:
 
 }  // namespace tests
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/unit_test/FileDirGuard.h b/src/test/unit_test/FileDirGuard.h
index 90765f7029..cf2eab7adb 100644
--- a/src/test/unit_test/FileDirGuard.h
+++ b/src/test/unit_test/FileDirGuard.h
@@ -1,5 +1,4 @@
-#ifndef TEST_UNIT_TEST_DIRGUARD_H
-#define TEST_UNIT_TEST_DIRGUARD_H
+#pragma once
 
 #include <test/jtx/TestSuite.h>
 
@@ -154,5 +153,3 @@ public:
 
 }  // namespace detail
 }  // namespace xrpl
-
-#endif  // TEST_UNIT_TEST_DIRGUARD_H
diff --git a/src/test/unit_test/SuiteJournal.h b/src/test/unit_test/SuiteJournal.h
index 0b87706056..ad5f298b74 100644
--- a/src/test/unit_test/SuiteJournal.h
+++ b/src/test/unit_test/SuiteJournal.h
@@ -1,5 +1,4 @@
-#ifndef TEST_UNIT_TEST_SUITE_JOURNAL_H
-#define TEST_UNIT_TEST_SUITE_JOURNAL_H
+#pragma once
 
 #include <xrpl/beast/unit_test.h>
 #include <xrpl/beast/utility/Journal.h>
@@ -133,5 +132,3 @@ public:
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/test/unit_test/multi_runner.h b/src/test/unit_test/multi_runner.h
index 25649d917f..28ecaf85f9 100644
--- a/src/test/unit_test/multi_runner.h
+++ b/src/test/unit_test/multi_runner.h
@@ -1,5 +1,4 @@
-#ifndef TEST_UNIT_TEST_MULTI_RUNNER_H
-#define TEST_UNIT_TEST_MULTI_RUNNER_H
+#pragma once
 
 #include <xrpl/beast/unit_test/global_suites.h>
 #include <xrpl/beast/unit_test/runner.h>
@@ -334,5 +333,3 @@ multi_runner_child::run_multi(Pred pred)
 
 }  // namespace test
 }  // namespace xrpl
-
-#endif
diff --git a/src/tests/libxrpl/helpers/TestSink.h b/src/tests/libxrpl/helpers/TestSink.h
index aa34e16838..daa40d014f 100644
--- a/src/tests/libxrpl/helpers/TestSink.h
+++ b/src/tests/libxrpl/helpers/TestSink.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_DEBUGSINK_H
-#define XRPL_DEBUGSINK_H
+#pragma once
 
 #include <xrpl/beast/utility/Journal.h>
 
@@ -23,4 +22,3 @@ public:
     writeAlways(beast::severities::Severity level, std::string const& text) override;
 };
 }  // namespace xrpl
-#endif  // XRPL_DEBUGSINK_H
diff --git a/src/xrpld/app/consensus/RCLCensorshipDetector.h b/src/xrpld/app/consensus/RCLCensorshipDetector.h
index 671337c118..fbdc6c2397 100644
--- a/src/xrpld/app/consensus/RCLCensorshipDetector.h
+++ b/src/xrpld/app/consensus/RCLCensorshipDetector.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_CONSENSUS_RCLCENSORSHIPDETECTOR_H_INCLUDED
-#define XRPL_APP_CONSENSUS_RCLCENSORSHIPDETECTOR_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/algorithm.h>
 #include <xrpl/shamap/SHAMap.h>
@@ -122,5 +121,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/consensus/RCLConsensus.h b/src/xrpld/app/consensus/RCLConsensus.h
index 476cb25715..3e1b27cd9c 100644
--- a/src/xrpld/app/consensus/RCLConsensus.h
+++ b/src/xrpld/app/consensus/RCLConsensus.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_CONSENSUS_RCLCONSENSUS_H_INCLUDED
-#define XRPL_APP_CONSENSUS_RCLCONSENSUS_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/consensus/RCLCensorshipDetector.h>
 #include <xrpld/app/consensus/RCLCxLedger.h>
@@ -524,5 +523,3 @@ public:
     }
 };
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/consensus/RCLCxLedger.h b/src/xrpld/app/consensus/RCLCxLedger.h
index 4413fee7fc..6b96fc8af3 100644
--- a/src/xrpld/app/consensus/RCLCxLedger.h
+++ b/src/xrpld/app/consensus/RCLCxLedger.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_CONSENSUS_RCLCXLEDGER_H_INCLUDED
-#define XRPL_APP_CONSENSUS_RCLCXLEDGER_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/Ledger.h>
 #include <xrpld/app/ledger/LedgerToJson.h>
@@ -101,4 +100,3 @@ public:
     std::shared_ptr<Ledger const> ledger_;
 };
 }  // namespace xrpl
-#endif
diff --git a/src/xrpld/app/consensus/RCLCxPeerPos.h b/src/xrpld/app/consensus/RCLCxPeerPos.h
index 78a8bfde1e..b9ef492aae 100644
--- a/src/xrpld/app/consensus/RCLCxPeerPos.h
+++ b/src/xrpld/app/consensus/RCLCxPeerPos.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_CONSENSUS_RCLCXPEERPOS_H_INCLUDED
-#define XRPL_APP_CONSENSUS_RCLCXPEERPOS_H_INCLUDED
+#pragma once
 
 #include <xrpld/consensus/ConsensusProposal.h>
 
@@ -125,5 +124,3 @@ proposalUniqueId(
     Slice const& signature);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/consensus/RCLCxTx.h b/src/xrpld/app/consensus/RCLCxTx.h
index a0cefcf199..b7bde11a3b 100644
--- a/src/xrpld/app/consensus/RCLCxTx.h
+++ b/src/xrpld/app/consensus/RCLCxTx.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_CONSENSUS_RCLCXTX_H_INCLUDED
-#define XRPL_APP_CONSENSUS_RCLCXTX_H_INCLUDED
+#pragma once
 
 #include <xrpl/shamap/SHAMap.h>
 
@@ -167,4 +166,3 @@ public:
     std::shared_ptr<SHAMap> map_;
 };
 }  // namespace xrpl
-#endif
diff --git a/src/xrpld/app/consensus/RCLValidations.h b/src/xrpld/app/consensus/RCLValidations.h
index 97ccb727fe..35c1686f9e 100644
--- a/src/xrpld/app/consensus/RCLValidations.h
+++ b/src/xrpld/app/consensus/RCLValidations.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_CONSENSUSS_VALIDATIONS_H_INCLUDED
-#define XRPL_APP_CONSENSUSS_VALIDATIONS_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/Ledger.h>
 #include <xrpld/consensus/Validations.h>
@@ -237,5 +236,3 @@ handleNewValidation(
     std::optional<beast::Journal> j = std::nullopt);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/AbstractFetchPackContainer.h b/src/xrpld/app/ledger/AbstractFetchPackContainer.h
index d2cdd1e920..3adc435bd6 100644
--- a/src/xrpld/app/ledger/AbstractFetchPackContainer.h
+++ b/src/xrpld/app/ledger/AbstractFetchPackContainer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_ABSTRACTFETCHPACKCONTAINER_H_INCLUDED
-#define XRPL_APP_LEDGER_ABSTRACTFETCHPACKCONTAINER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Blob.h>
 #include <xrpl/basics/base_uint.h>
@@ -27,5 +26,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/AcceptedLedger.h b/src/xrpld/app/ledger/AcceptedLedger.h
index 37e5d01a26..c0f186c781 100644
--- a/src/xrpld/app/ledger/AcceptedLedger.h
+++ b/src/xrpld/app/ledger/AcceptedLedger.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_ACCEPTEDLEDGER_H_INCLUDED
-#define XRPL_APP_LEDGER_ACCEPTEDLEDGER_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/AcceptedLedgerTx.h>
 
@@ -56,5 +55,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/AcceptedLedgerTx.h b/src/xrpld/app/ledger/AcceptedLedgerTx.h
index efea5b9162..6c936bbcf2 100644
--- a/src/xrpld/app/ledger/AcceptedLedgerTx.h
+++ b/src/xrpld/app/ledger/AcceptedLedgerTx.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_ACCEPTEDLEDGERTX_H_INCLUDED
-#define XRPL_APP_LEDGER_ACCEPTEDLEDGERTX_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/Ledger.h>
 
@@ -86,5 +85,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/AccountStateSF.h b/src/xrpld/app/ledger/AccountStateSF.h
index 40f40ac8a1..fb9da3a616 100644
--- a/src/xrpld/app/ledger/AccountStateSF.h
+++ b/src/xrpld/app/ledger/AccountStateSF.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_ACCOUNTSTATESF_H_INCLUDED
-#define XRPL_APP_LEDGER_ACCOUNTSTATESF_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/AbstractFetchPackContainer.h>
 
@@ -30,5 +29,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/BookListeners.h b/src/xrpld/app/ledger/BookListeners.h
index 784172974e..036e988749 100644
--- a/src/xrpld/app/ledger/BookListeners.h
+++ b/src/xrpld/app/ledger/BookListeners.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_BOOKLISTENERS_H_INCLUDED
-#define XRPL_APP_LEDGER_BOOKLISTENERS_H_INCLUDED
+#pragma once
 
 #include <xrpld/rpc/InfoSub.h>
 
@@ -51,5 +50,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/BuildLedger.h b/src/xrpld/app/ledger/BuildLedger.h
index 24b9e988ff..7b4b85c4aa 100644
--- a/src/xrpld/app/ledger/BuildLedger.h
+++ b/src/xrpld/app/ledger/BuildLedger.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_BUILD_LEDGER_H_INCLUDED
-#define XRPL_APP_LEDGER_BUILD_LEDGER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/chrono.h>
 #include <xrpl/beast/utility/Journal.h>
@@ -54,4 +53,3 @@ std::shared_ptr<Ledger>
 buildLedger(LedgerReplay const& replayData, ApplyFlags applyFlags, Application& app, beast::Journal j);
 
 }  // namespace xrpl
-#endif
diff --git a/src/xrpld/app/ledger/ConsensusTransSetSF.h b/src/xrpld/app/ledger/ConsensusTransSetSF.h
index 1e9acefc38..855577ecee 100644
--- a/src/xrpld/app/ledger/ConsensusTransSetSF.h
+++ b/src/xrpld/app/ledger/ConsensusTransSetSF.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_CONSENSUSTRANSSETSF_H_INCLUDED
-#define XRPL_APP_LEDGER_CONSENSUSTRANSSETSF_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/main/Application.h>
 
@@ -35,5 +34,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/InboundLedger.h b/src/xrpld/app/ledger/InboundLedger.h
index c062b83143..46a8cf19b5 100644
--- a/src/xrpld/app/ledger/InboundLedger.h
+++ b/src/xrpld/app/ledger/InboundLedger.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_INBOUNDLEDGER_H_INCLUDED
-#define XRPL_APP_LEDGER_INBOUNDLEDGER_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/Ledger.h>
 #include <xrpld/app/ledger/detail/TimeoutCounter.h>
@@ -173,5 +172,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/InboundLedgers.h b/src/xrpld/app/ledger/InboundLedgers.h
index 6b4b1a6ef0..30eb69ab7a 100644
--- a/src/xrpld/app/ledger/InboundLedgers.h
+++ b/src/xrpld/app/ledger/InboundLedgers.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_INBOUNDLEDGERS_H_INCLUDED
-#define XRPL_APP_LEDGER_INBOUNDLEDGERS_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/InboundLedger.h>
 
@@ -79,5 +78,3 @@ make_InboundLedgers(
     beast::insight::Collector::ptr const& collector);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/InboundTransactions.h b/src/xrpld/app/ledger/InboundTransactions.h
index e905fb1846..7b85f56c5f 100644
--- a/src/xrpld/app/ledger/InboundTransactions.h
+++ b/src/xrpld/app/ledger/InboundTransactions.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_INBOUNDTRANSACTIONS_H_INCLUDED
-#define XRPL_APP_LEDGER_INBOUNDTRANSACTIONS_H_INCLUDED
+#pragma once
 
 #include <xrpld/overlay/Peer.h>
 
@@ -73,5 +72,3 @@ make_InboundTransactions(
     std::function<void(std::shared_ptr<SHAMap> const&, bool)> gotSet);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/Ledger.h b/src/xrpld/app/ledger/Ledger.h
index a8c9b91342..cbfbc0030f 100644
--- a/src/xrpld/app/ledger/Ledger.h
+++ b/src/xrpld/app/ledger/Ledger.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_LEDGER_H_INCLUDED
-#define XRPL_APP_LEDGER_LEDGER_H_INCLUDED
+#pragma once
 
 #include <xrpld/core/Config.h>
 #include <xrpld/core/TimeKeeper.h>
@@ -444,5 +443,3 @@ uint256
 calculateLedgerHash(LedgerHeader const& info);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/LedgerCleaner.h b/src/xrpld/app/ledger/LedgerCleaner.h
index 2377485f22..aa8d042c24 100644
--- a/src/xrpld/app/ledger/LedgerCleaner.h
+++ b/src/xrpld/app/ledger/LedgerCleaner.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_LEDGERCLEANER_H_INCLUDED
-#define XRPL_APP_LEDGER_LEDGERCLEANER_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/main/Application.h>
 
@@ -44,5 +43,3 @@ std::unique_ptr<LedgerCleaner>
 make_LedgerCleaner(Application& app, beast::Journal journal);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/LedgerHistory.h b/src/xrpld/app/ledger/LedgerHistory.h
index 4beaa10ad4..6713dcbe1e 100644
--- a/src/xrpld/app/ledger/LedgerHistory.h
+++ b/src/xrpld/app/ledger/LedgerHistory.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_LEDGERHISTORY_H_INCLUDED
-#define XRPL_APP_LEDGER_LEDGERHISTORY_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/Ledger.h>
 #include <xrpld/app/main/Application.h>
@@ -130,5 +129,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/LedgerHolder.h b/src/xrpld/app/ledger/LedgerHolder.h
index c0a81778ae..8d2ac9f308 100644
--- a/src/xrpld/app/ledger/LedgerHolder.h
+++ b/src/xrpld/app/ledger/LedgerHolder.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_LEDGERHOLDER_H_INCLUDED
-#define XRPL_APP_LEDGER_LEDGERHOLDER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/basics/contract.h>
@@ -54,5 +53,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/LedgerMaster.h b/src/xrpld/app/ledger/LedgerMaster.h
index 5db8806534..ceb9fa9045 100644
--- a/src/xrpld/app/ledger/LedgerMaster.h
+++ b/src/xrpld/app/ledger/LedgerMaster.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_LEDGERMASTER_H_INCLUDED
-#define XRPL_APP_LEDGER_LEDGERMASTER_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/AbstractFetchPackContainer.h>
 #include <xrpld/app/ledger/InboundLedgers.h>
@@ -391,5 +390,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/LedgerReplay.h b/src/xrpld/app/ledger/LedgerReplay.h
index 9051bb414c..f4cbf9c69e 100644
--- a/src/xrpld/app/ledger/LedgerReplay.h
+++ b/src/xrpld/app/ledger/LedgerReplay.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_LEDGERREPLAY_H_INCLUDED
-#define XRPL_APP_LEDGER_LEDGERREPLAY_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 
@@ -51,5 +50,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/LedgerReplayTask.h b/src/xrpld/app/ledger/LedgerReplayTask.h
index 40995430db..94eeee5f51 100644
--- a/src/xrpld/app/ledger/LedgerReplayTask.h
+++ b/src/xrpld/app/ledger/LedgerReplayTask.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_LEDGERREPLAYTASK_H_INCLUDED
-#define XRPL_APP_LEDGER_LEDGERREPLAYTASK_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/InboundLedger.h>
 #include <xrpld/app/ledger/detail/TimeoutCounter.h>
@@ -152,5 +151,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/LedgerReplayer.h b/src/xrpld/app/ledger/LedgerReplayer.h
index ff67a43e87..0d08e5a76f 100644
--- a/src/xrpld/app/ledger/LedgerReplayer.h
+++ b/src/xrpld/app/ledger/LedgerReplayer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_LEDGERREPLAYER_H_INCLUDED
-#define XRPL_APP_LEDGER_LEDGERREPLAYER_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/LedgerMaster.h>
 #include <xrpld/app/ledger/LedgerReplayTask.h>
@@ -132,5 +131,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/LedgerToJson.h b/src/xrpld/app/ledger/LedgerToJson.h
index 1d77c4dc39..8cde134d23 100644
--- a/src/xrpld/app/ledger/LedgerToJson.h
+++ b/src/xrpld/app/ledger/LedgerToJson.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_LEDGERTOJSON_H_INCLUDED
-#define XRPL_APP_LEDGER_LEDGERTOJSON_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/Ledger.h>
 #include <xrpld/app/ledger/LedgerMaster.h>
@@ -44,5 +43,3 @@ void
 copyFrom(Json::Value& to, Json::Value const& from);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/LocalTxs.h b/src/xrpld/app/ledger/LocalTxs.h
index d02e1027a0..34dfede40f 100644
--- a/src/xrpld/app/ledger/LocalTxs.h
+++ b/src/xrpld/app/ledger/LocalTxs.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_LOCALTXS_H_INCLUDED
-#define XRPL_APP_LEDGER_LOCALTXS_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/misc/CanonicalTXSet.h>
 
@@ -43,5 +42,3 @@ std::unique_ptr<LocalTxs>
 make_LocalTxs();
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/OpenLedger.h b/src/xrpld/app/ledger/OpenLedger.h
index 498e140b4b..187086862c 100644
--- a/src/xrpld/app/ledger/OpenLedger.h
+++ b/src/xrpld/app/ledger/OpenLedger.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_OPENLEDGER_H_INCLUDED
-#define XRPL_APP_LEDGER_OPENLEDGER_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/Ledger.h>
 #include <xrpld/app/misc/CanonicalTXSet.h>
@@ -262,5 +261,3 @@ std::string
 debugTostr(std::shared_ptr<ReadView const> const& view);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/OrderBookDB.h b/src/xrpld/app/ledger/OrderBookDB.h
index 601b2d38e4..da604d7e22 100644
--- a/src/xrpld/app/ledger/OrderBookDB.h
+++ b/src/xrpld/app/ledger/OrderBookDB.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_ORDERBOOKDB_H_INCLUDED
-#define XRPL_APP_LEDGER_ORDERBOOKDB_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/AcceptedLedgerTx.h>
 #include <xrpld/app/ledger/BookListeners.h>
@@ -74,5 +73,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/PendingSaves.h b/src/xrpld/app/ledger/PendingSaves.h
index 24eb50e568..76958fc78a 100644
--- a/src/xrpld/app/ledger/PendingSaves.h
+++ b/src/xrpld/app/ledger/PendingSaves.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_PENDINGSAVES_H_INCLUDED
-#define XRPL_APP_PENDINGSAVES_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/Protocol.h>
 
@@ -125,5 +124,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/TransactionMaster.h b/src/xrpld/app/ledger/TransactionMaster.h
index ceba55a85a..039ff5cb99 100644
--- a/src/xrpld/app/ledger/TransactionMaster.h
+++ b/src/xrpld/app/ledger/TransactionMaster.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_TRANSACTIONMASTER_H_INCLUDED
-#define XRPL_APP_LEDGER_TRANSACTIONMASTER_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/misc/Transaction.h>
 
@@ -64,5 +63,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/TransactionStateSF.h b/src/xrpld/app/ledger/TransactionStateSF.h
index 0ea8d7fb2d..2851884cfd 100644
--- a/src/xrpld/app/ledger/TransactionStateSF.h
+++ b/src/xrpld/app/ledger/TransactionStateSF.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_TRANSACTIONSTATESF_H_INCLUDED
-#define XRPL_APP_LEDGER_TRANSACTIONSTATESF_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/AbstractFetchPackContainer.h>
 
@@ -30,5 +29,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/detail/LedgerDeltaAcquire.h b/src/xrpld/app/ledger/detail/LedgerDeltaAcquire.h
index 7b4d478c13..66b8f27b85 100644
--- a/src/xrpld/app/ledger/detail/LedgerDeltaAcquire.h
+++ b/src/xrpld/app/ledger/detail/LedgerDeltaAcquire.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_LEDGERDELTAACQUIRE_H_INCLUDED
-#define XRPL_APP_LEDGER_LEDGERDELTAACQUIRE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/InboundLedger.h>
 #include <xrpld/app/ledger/Ledger.h>
@@ -137,5 +136,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/detail/LedgerReplayMsgHandler.h b/src/xrpld/app/ledger/detail/LedgerReplayMsgHandler.h
index 7cd231e59a..260f1ff753 100644
--- a/src/xrpld/app/ledger/detail/LedgerReplayMsgHandler.h
+++ b/src/xrpld/app/ledger/detail/LedgerReplayMsgHandler.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_LEDGERREPLAYMSGHANDLER_H_INCLUDED
-#define XRPL_APP_LEDGER_LEDGERREPLAYMSGHANDLER_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/Journal.h>
 #include <xrpl/protocol/messages.h>
@@ -51,5 +50,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/detail/SkipListAcquire.h b/src/xrpld/app/ledger/detail/SkipListAcquire.h
index 587f6c19fd..f3bfb60bee 100644
--- a/src/xrpld/app/ledger/detail/SkipListAcquire.h
+++ b/src/xrpld/app/ledger/detail/SkipListAcquire.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_SKIPLISTACQUIRE_H_INCLUDED
-#define XRPL_APP_LEDGER_SKIPLISTACQUIRE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/InboundLedger.h>
 #include <xrpld/app/ledger/Ledger.h>
@@ -134,5 +133,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/detail/TimeoutCounter.h b/src/xrpld/app/ledger/detail/TimeoutCounter.h
index c228d50aac..5f5ccb2f43 100644
--- a/src/xrpld/app/ledger/detail/TimeoutCounter.h
+++ b/src/xrpld/app/ledger/detail/TimeoutCounter.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_TIMEOUTCOUNTER_H_INCLUDED
-#define XRPL_APP_LEDGER_TIMEOUTCOUNTER_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/main/Application.h>
 
@@ -131,5 +130,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/ledger/detail/TransactionAcquire.h b/src/xrpld/app/ledger/detail/TransactionAcquire.h
index dd12e8afb0..4345c74fc6 100644
--- a/src/xrpld/app/ledger/detail/TransactionAcquire.h
+++ b/src/xrpld/app/ledger/detail/TransactionAcquire.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_TRANSACTIONACQUIRE_H_INCLUDED
-#define XRPL_APP_LEDGER_TRANSACTIONACQUIRE_H_INCLUDED
+#pragma once
 
 #include <xrpld/overlay/PeerSet.h>
 
@@ -49,5 +48,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/main/Application.h b/src/xrpld/app/main/Application.h
index bb8bac8bbb..53cc264ad4 100644
--- a/src/xrpld/app/main/Application.h
+++ b/src/xrpld/app/main/Application.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MAIN_APPLICATION_H_INCLUDED
-#define XRPL_APP_MAIN_APPLICATION_H_INCLUDED
+#pragma once
 
 #include <xrpld/core/Config.h>
 #include <xrpld/overlay/PeerReservationTable.h>
@@ -183,5 +182,3 @@ std::unique_ptr<Application>
 make_Application(std::unique_ptr<Config> config, std::unique_ptr<Logs> logs, std::unique_ptr<TimeKeeper> timeKeeper);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/main/BasicApp.h b/src/xrpld/app/main/BasicApp.h
index 0d38260e43..278c255af3 100644
--- a/src/xrpld/app/main/BasicApp.h
+++ b/src/xrpld/app/main/BasicApp.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_BASICAPP_H_INCLUDED
-#define XRPL_APP_BASICAPP_H_INCLUDED
+#pragma once
 
 #include <boost/asio/io_context.hpp>
 
@@ -25,5 +24,3 @@ public:
         return io_context_;
     }
 };
-
-#endif
diff --git a/src/xrpld/app/main/CollectorManager.h b/src/xrpld/app/main/CollectorManager.h
index d0d202625c..15785ec292 100644
--- a/src/xrpld/app/main/CollectorManager.h
+++ b/src/xrpld/app/main/CollectorManager.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MAIN_COLLECTORMANAGER_H_INCLUDED
-#define XRPL_APP_MAIN_COLLECTORMANAGER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/BasicConfig.h>
 #include <xrpl/beast/insight/Insight.h>
@@ -23,5 +22,3 @@ std::unique_ptr<CollectorManager>
 make_CollectorManager(Section const& params, beast::Journal journal);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/main/DBInit.h b/src/xrpld/app/main/DBInit.h
index 60ff4b498b..56bc752343 100644
--- a/src/xrpld/app/main/DBInit.h
+++ b/src/xrpld/app/main/DBInit.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_DATA_DBINIT_H_INCLUDED
-#define XRPL_APP_DATA_DBINIT_H_INCLUDED
+#pragma once
 
 #include <array>
 #include <cstdint>
@@ -117,5 +116,3 @@ inline constexpr std::array<char const*, 6> WalletDBInit{
      "END TRANSACTION;"}};
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/main/GRPCServer.h b/src/xrpld/app/main/GRPCServer.h
index 67748c359d..fdac2b6484 100644
--- a/src/xrpld/app/main/GRPCServer.h
+++ b/src/xrpld/app/main/GRPCServer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CORE_GRPCSERVER_H_INCLUDED
-#define XRPL_CORE_GRPCSERVER_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/main/Application.h>
 #include <xrpld/rpc/Context.h>
@@ -300,4 +299,3 @@ private:
     bool running_ = false;
 };
 }  // namespace xrpl
-#endif
diff --git a/src/xrpld/app/main/LoadManager.h b/src/xrpld/app/main/LoadManager.h
index 15caa9b0f0..c36afb1804 100644
--- a/src/xrpld/app/main/LoadManager.h
+++ b/src/xrpld/app/main/LoadManager.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MAIN_LOADMANAGER_H_INCLUDED
-#define XRPL_APP_MAIN_LOADMANAGER_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/Journal.h>
 
@@ -95,5 +94,3 @@ std::unique_ptr<LoadManager>
 make_LoadManager(Application& app, beast::Journal journal);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/main/NodeIdentity.h b/src/xrpld/app/main/NodeIdentity.h
index ca47ae72ae..bebd5c261d 100644
--- a/src/xrpld/app/main/NodeIdentity.h
+++ b/src/xrpld/app/main/NodeIdentity.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MAIN_NODEIDENTITY_H_INCLUDED
-#define XRPL_APP_MAIN_NODEIDENTITY_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/main/Application.h>
 
@@ -19,5 +18,3 @@ std::pair<PublicKey, SecretKey>
 getNodeIdentity(Application& app, boost::program_options::variables_map const& cmdline);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/main/NodeStoreScheduler.h b/src/xrpld/app/main/NodeStoreScheduler.h
index 0214b76660..19e8d9d212 100644
--- a/src/xrpld/app/main/NodeStoreScheduler.h
+++ b/src/xrpld/app/main/NodeStoreScheduler.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MAIN_NODESTORESCHEDULER_H_INCLUDED
-#define XRPL_APP_MAIN_NODESTORESCHEDULER_H_INCLUDED
+#pragma once
 
 #include <xrpl/core/JobQueue.h>
 #include <xrpl/nodestore/Scheduler.h>
@@ -24,5 +23,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/main/Tuning.h b/src/xrpld/app/main/Tuning.h
index 25cc2ef75d..0f612b1b1c 100644
--- a/src/xrpld/app/main/Tuning.h
+++ b/src/xrpld/app/main/Tuning.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MAIN_TUNING_H_INCLUDED
-#define XRPL_APP_MAIN_TUNING_H_INCLUDED
+#pragma once
 
 #include <chrono>
 
@@ -11,5 +10,3 @@ constexpr std::chrono::seconds fullBelowExpiration = std::chrono::minutes{10};
 constexpr std::size_t maxPoppedTransactions = 10;
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/AMMHelpers.h b/src/xrpld/app/misc/AMMHelpers.h
index e54eea2f01..cde485f5dc 100644
--- a/src/xrpld/app/misc/AMMHelpers.h
+++ b/src/xrpld/app/misc/AMMHelpers.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_AMMHELPERS_H_INCLUDED
-#define XRPL_APP_MISC_AMMHELPERS_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/basics/Number.h>
@@ -688,5 +687,3 @@ Number
 adjustFracByTokens(Rules const& rules, STAmount const& lptAMMBalance, STAmount const& tokens, Number const& frac);
 
 }  // namespace xrpl
-
-#endif  // XRPL_APP_MISC_AMMHELPERS_H_INCLUDED
diff --git a/src/xrpld/app/misc/AMMUtils.h b/src/xrpld/app/misc/AMMUtils.h
index 5ed03d51f7..c97397a141 100644
--- a/src/xrpld/app/misc/AMMUtils.h
+++ b/src/xrpld/app/misc/AMMUtils.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_AMMUTILS_H_INCLUDED
-#define XRPL_APP_MISC_AMMUTILS_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Expected.h>
 #include <xrpl/beast/utility/Journal.h>
@@ -100,5 +99,3 @@ verifyAndAdjustLPTokenBalance(
     AccountID const& account);
 
 }  // namespace xrpl
-
-#endif  // XRPL_APP_MISC_AMMUTILS_H_INCLUDED
diff --git a/src/xrpld/app/misc/AmendmentTable.h b/src/xrpld/app/misc/AmendmentTable.h
index d6cb3d7bce..94ac9608a7 100644
--- a/src/xrpld/app/misc/AmendmentTable.h
+++ b/src/xrpld/app/misc/AmendmentTable.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_AMENDMENTTABLE_H_INCLUDED
-#define XRPL_APP_MISC_AMENDMENTTABLE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/Ledger.h>
 #include <xrpld/core/ConfigSections.h>
@@ -172,5 +171,3 @@ make_AmendmentTable(
     beast::Journal journal);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/CanonicalTXSet.h b/src/xrpld/app/misc/CanonicalTXSet.h
index 15fb656403..45f58b5701 100644
--- a/src/xrpld/app/misc/CanonicalTXSet.h
+++ b/src/xrpld/app/misc/CanonicalTXSet.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_CANONICALTXSET_H_INCLUDED
-#define XRPL_APP_MISC_CANONICALTXSET_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/protocol/RippleLedgerHash.h>
@@ -156,5 +155,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/DelegateUtils.h b/src/xrpld/app/misc/DelegateUtils.h
index 37d9195a82..78ccc46d0b 100644
--- a/src/xrpld/app/misc/DelegateUtils.h
+++ b/src/xrpld/app/misc/DelegateUtils.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_DELEGATEUTILS_H_INCLUDED
-#define XRPL_APP_MISC_DELEGATEUTILS_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/Permissions.h>
 #include <xrpl/protocol/STLedgerEntry.h>
@@ -34,5 +33,3 @@ loadGranularPermission(
     std::unordered_set<GranularPermissionType>& granularPermissions);
 
 }  // namespace xrpl
-
-#endif  // XRPL_APP_MISC_DELEGATEUTILS_H_INCLUDED
diff --git a/src/xrpld/app/misc/DeliverMax.h b/src/xrpld/app/misc/DeliverMax.h
index e9455354f8..1b4241f091 100644
--- a/src/xrpld/app/misc/DeliverMax.h
+++ b/src/xrpld/app/misc/DeliverMax.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_DELIVERMAX_H_INCLUDED
-#define XRPL_APP_MISC_DELIVERMAX_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/TxFormats.h>
 
@@ -27,5 +26,3 @@ insertDeliverMax(Json::Value& tx_json, TxType txnType, unsigned int apiVersion);
 
 }  // namespace RPC
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/FeeVote.h b/src/xrpld/app/misc/FeeVote.h
index 4b7f7f8409..3ecf474867 100644
--- a/src/xrpld/app/misc/FeeVote.h
+++ b/src/xrpld/app/misc/FeeVote.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_FEEVOTE_H_INCLUDED
-#define XRPL_APP_MISC_FEEVOTE_H_INCLUDED
+#pragma once
 
 #include <xrpl/ledger/ReadView.h>
 #include <xrpl/protocol/STValidation.h>
@@ -42,5 +41,3 @@ std::unique_ptr<FeeVote>
 make_FeeVote(FeeSetup const& setup, beast::Journal journal);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/HashRouter.h b/src/xrpld/app/misc/HashRouter.h
index d4ff8629f3..ad6da520bd 100644
--- a/src/xrpld/app/misc/HashRouter.h
+++ b/src/xrpld/app/misc/HashRouter.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_HASHROUTER_H_INCLUDED
-#define XRPL_APP_MISC_HASHROUTER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/basics/UnorderedContainers.h>
@@ -256,5 +255,3 @@ HashRouter::Setup
 setup_HashRouter(Config const&);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/LendingHelpers.h b/src/xrpld/app/misc/LendingHelpers.h
index 0e04f0f793..f8297dfdf7 100644
--- a/src/xrpld/app/misc/LendingHelpers.h
+++ b/src/xrpld/app/misc/LendingHelpers.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_LENDINGHELPERS_H_INCLUDED
-#define XRPL_APP_MISC_LENDINGHELPERS_H_INCLUDED
+#pragma once
 
 #include <xrpl/ledger/View.h>
 #include <xrpl/protocol/st.h>
@@ -466,5 +465,3 @@ loanMakePayment(
     beast::Journal j);
 
 }  // namespace xrpl
-
-#endif  // XRPL_APP_MISC_LENDINGHELPERS_H_INCLUDED
diff --git a/src/xrpld/app/misc/LoadFeeTrack.h b/src/xrpld/app/misc/LoadFeeTrack.h
index 3c6932fa41..8eb53187ce 100644
--- a/src/xrpld/app/misc/LoadFeeTrack.h
+++ b/src/xrpld/app/misc/LoadFeeTrack.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CORE_LOADFEETRACK_H_INCLUDED
-#define XRPL_CORE_LOADFEETRACK_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/beast/utility/Journal.h>
@@ -136,5 +135,3 @@ XRPAmount
 scaleFeeLoad(XRPAmount fee, LoadFeeTrack const& feeTrack, Fees const& fees, bool bUnlimited);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/Manifest.h b/src/xrpld/app/misc/Manifest.h
index a41e16dbf9..79426a1a46 100644
--- a/src/xrpld/app/misc/Manifest.h
+++ b/src/xrpld/app/misc/Manifest.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_MANIFEST_H_INCLUDED
-#define XRPL_APP_MISC_MANIFEST_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/UnorderedContainers.h>
 #include <xrpl/beast/utility/Journal.h>
@@ -427,5 +426,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/NegativeUNLVote.h b/src/xrpld/app/misc/NegativeUNLVote.h
index 68daa0e57b..4019d32f13 100644
--- a/src/xrpld/app/misc/NegativeUNLVote.h
+++ b/src/xrpld/app/misc/NegativeUNLVote.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_NEGATIVEUNLVOTE_H_INCLUDED
-#define XRPL_APP_MISC_NEGATIVEUNLVOTE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/Ledger.h>
 
@@ -188,5 +187,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/NetworkOPs.h b/src/xrpld/app/misc/NetworkOPs.h
index 7e230510a8..66c915008a 100644
--- a/src/xrpld/app/misc/NetworkOPs.h
+++ b/src/xrpld/app/misc/NetworkOPs.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_NETWORKOPS_H_INCLUDED
-#define XRPL_APP_MISC_NETWORKOPS_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/consensus/RCLCxPeerPos.h>
 #include <xrpld/app/ledger/Ledger.h>
@@ -263,5 +262,3 @@ make_NetworkOPs(
     beast::insight::Collector::ptr const& collector);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/SHAMapStore.h b/src/xrpld/app/misc/SHAMapStore.h
index 30253d92a5..67477593cb 100644
--- a/src/xrpld/app/misc/SHAMapStore.h
+++ b/src/xrpld/app/misc/SHAMapStore.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_SHAMAPSTORE_H_INCLUDED
-#define XRPL_APP_MISC_SHAMAPSTORE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/Ledger.h>
 
@@ -86,5 +85,3 @@ public:
 std::unique_ptr<SHAMapStore>
 make_SHAMapStore(Application& app, NodeStore::Scheduler& scheduler, beast::Journal journal);
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/SHAMapStoreImp.h b/src/xrpld/app/misc/SHAMapStoreImp.h
index 05faae5bd4..a0475e80d6 100644
--- a/src/xrpld/app/misc/SHAMapStoreImp.h
+++ b/src/xrpld/app/misc/SHAMapStoreImp.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_SHAMAPSTOREIMP_H_INCLUDED
-#define XRPL_APP_MISC_SHAMAPSTOREIMP_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/LedgerMaster.h>
 #include <xrpld/app/misc/SHAMapStore.h>
@@ -221,5 +220,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/Transaction.h b/src/xrpld/app/misc/Transaction.h
index c902d4a4f3..22f3e9d1fd 100644
--- a/src/xrpld/app/misc/Transaction.h
+++ b/src/xrpld/app/misc/Transaction.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_TRANSACTION_H_INCLUDED
-#define XRPL_APP_MISC_TRANSACTION_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/RangeSet.h>
 #include <xrpl/beast/utility/Journal.h>
@@ -386,5 +385,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/TxQ.h b/src/xrpld/app/misc/TxQ.h
index 004cd085fc..b50ff1a0b5 100644
--- a/src/xrpld/app/misc/TxQ.h
+++ b/src/xrpld/app/misc/TxQ.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TXQ_H_INCLUDED
-#define XRPL_TXQ_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/applySteps.h>
 
@@ -825,5 +824,3 @@ toFeeLevel(XRPAmount const& drops, XRPAmount const& baseFee)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/ValidatorKeys.h b/src/xrpld/app/misc/ValidatorKeys.h
index 3a9aaf6d2c..296c63e09e 100644
--- a/src/xrpld/app/misc/ValidatorKeys.h
+++ b/src/xrpld/app/misc/ValidatorKeys.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_VALIDATOR_KEYS_H_INCLUDED
-#define XRPL_APP_MISC_VALIDATOR_KEYS_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/Journal.h>
 #include <xrpl/protocol/PublicKey.h>
@@ -55,5 +54,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/ValidatorList.h b/src/xrpld/app/misc/ValidatorList.h
index 3b15af00dc..4fd610be04 100644
--- a/src/xrpld/app/misc/ValidatorList.h
+++ b/src/xrpld/app/misc/ValidatorList.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_VALIDATORLIST_H_INCLUDED
-#define XRPL_APP_MISC_VALIDATORLIST_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/misc/Manifest.h>
 #include <xrpld/core/TimeKeeper.h>
@@ -926,5 +925,3 @@ hash_append(Hasher& h, TMValidatorListCollection const& msg)
 }
 
 }  // namespace protocol
-
-#endif
diff --git a/src/xrpld/app/misc/ValidatorSite.h b/src/xrpld/app/misc/ValidatorSite.h
index 075722bca6..dc44e28bcb 100644
--- a/src/xrpld/app/misc/ValidatorSite.h
+++ b/src/xrpld/app/misc/ValidatorSite.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_VALIDATORSITE_H_INCLUDED
-#define XRPL_APP_MISC_VALIDATORSITE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/main/Application.h>
 #include <xrpld/app/misc/ValidatorList.h>
@@ -227,5 +226,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/detail/AccountTxPaging.h b/src/xrpld/app/misc/detail/AccountTxPaging.h
index cbfe8c89bb..6dff5c481b 100644
--- a/src/xrpld/app/misc/detail/AccountTxPaging.h
+++ b/src/xrpld/app/misc/detail/AccountTxPaging.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_IMPL_ACCOUNTTXPAGING_H_INCLUDED
-#define XRPL_APP_MISC_IMPL_ACCOUNTTXPAGING_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/rdb/RelationalDatabase.h>
 
@@ -22,5 +21,3 @@ void
 saveLedgerAsync(Application& app, std::uint32_t seq);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/detail/Work.h b/src/xrpld/app/misc/detail/Work.h
index 90e81b7bbf..5261cf3bd7 100644
--- a/src/xrpld/app/misc/detail/Work.h
+++ b/src/xrpld/app/misc/detail/Work.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_DETAIL_WORK_H_INCLUDED
-#define XRPL_APP_MISC_DETAIL_WORK_H_INCLUDED
+#pragma once
 
 #include <boost/beast/http/message.hpp>
 #include <boost/beast/http/string_body.hpp>
@@ -25,5 +24,3 @@ public:
 }  // namespace detail
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/detail/WorkBase.h b/src/xrpld/app/misc/detail/WorkBase.h
index 1e519c7b2f..e5fd72f118 100644
--- a/src/xrpld/app/misc/detail/WorkBase.h
+++ b/src/xrpld/app/misc/detail/WorkBase.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_DETAIL_WORKBASE_H_INCLUDED
-#define XRPL_APP_MISC_DETAIL_WORKBASE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/misc/detail/Work.h>
 
@@ -258,5 +257,3 @@ WorkBase<Impl>::close()
 }  // namespace detail
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/detail/WorkFile.h b/src/xrpld/app/misc/detail/WorkFile.h
index cce7fd410e..8d2d4edb50 100644
--- a/src/xrpld/app/misc/detail/WorkFile.h
+++ b/src/xrpld/app/misc/detail/WorkFile.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_DETAIL_WORKFILE_H_INCLUDED
-#define XRPL_APP_MISC_DETAIL_WORKFILE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/misc/detail/Work.h>
 
@@ -80,5 +79,3 @@ WorkFile::cancel()
 }  // namespace detail
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/detail/WorkPlain.h b/src/xrpld/app/misc/detail/WorkPlain.h
index cac6d76a62..d1df5b4b3b 100644
--- a/src/xrpld/app/misc/detail/WorkPlain.h
+++ b/src/xrpld/app/misc/detail/WorkPlain.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_DETAIL_WORKPLAIN_H_INCLUDED
-#define XRPL_APP_MISC_DETAIL_WORKPLAIN_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/misc/detail/WorkBase.h>
 
@@ -60,5 +59,3 @@ WorkPlain::onConnect(error_code const& ec)
 }  // namespace detail
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/misc/detail/WorkSSL.h b/src/xrpld/app/misc/detail/WorkSSL.h
index bed963d8ec..b12c774f6e 100644
--- a/src/xrpld/app/misc/detail/WorkSSL.h
+++ b/src/xrpld/app/misc/detail/WorkSSL.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_MISC_DETAIL_WORKSSL_H_INCLUDED
-#define XRPL_APP_MISC_DETAIL_WORKSSL_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/misc/detail/WorkBase.h>
 #include <xrpld/core/Config.h>
@@ -57,5 +56,3 @@ private:
 }  // namespace detail
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/paths/AMMContext.h b/src/xrpld/app/paths/AMMContext.h
index 9e82a7394a..b0ff44c5ec 100644
--- a/src/xrpld/app/paths/AMMContext.h
+++ b/src/xrpld/app/paths/AMMContext.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_PATHS_AMMCONTEXT_H_INCLUDED
-#define XRPL_APP_PATHS_AMMCONTEXT_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/AccountID.h>
 
@@ -95,5 +94,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif  // XRPL_APP_PATHS_AMMCONTEXT_H_INCLUDED
diff --git a/src/xrpld/app/paths/AMMLiquidity.h b/src/xrpld/app/paths/AMMLiquidity.h
index c22901b28e..441c3b6e3d 100644
--- a/src/xrpld/app/paths/AMMLiquidity.h
+++ b/src/xrpld/app/paths/AMMLiquidity.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_TX_AMMLIQUIDITY_H_INCLUDED
-#define XRPL_APP_TX_AMMLIQUIDITY_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/misc/AMMHelpers.h>
 #include <xrpld/app/misc/AMMUtils.h>
@@ -131,5 +130,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif  // XRPL_APP_TX_AMMLIQUIDITY_H_INCLUDED
diff --git a/src/xrpld/app/paths/AMMOffer.h b/src/xrpld/app/paths/AMMOffer.h
index 893938f0f2..ebaa7311c0 100644
--- a/src/xrpld/app/paths/AMMOffer.h
+++ b/src/xrpld/app/paths/AMMOffer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_AMMOFFER_H_INCLUDED
-#define XRPL_APP_AMMOFFER_H_INCLUDED
+#pragma once
 
 #include <xrpl/ledger/ApplyView.h>
 #include <xrpl/ledger/View.h>
@@ -124,5 +123,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif  // XRPL_APP_AMMOFFER_H_INCLUDED
diff --git a/src/xrpld/app/paths/AccountCurrencies.h b/src/xrpld/app/paths/AccountCurrencies.h
index f0fa1bc504..eb8cc92aec 100644
--- a/src/xrpld/app/paths/AccountCurrencies.h
+++ b/src/xrpld/app/paths/AccountCurrencies.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_PATHS_ACCOUNTCURRENCIES_H_INCLUDED
-#define XRPL_APP_PATHS_ACCOUNTCURRENCIES_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/paths/RippleLineCache.h>
 
@@ -14,5 +13,3 @@ hash_set<Currency>
 accountSourceCurrencies(AccountID const& account, std::shared_ptr<RippleLineCache> const& lrLedger, bool includeXRP);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/paths/Flow.h b/src/xrpld/app/paths/Flow.h
index 5fafe294db..1a46ce221a 100644
--- a/src/xrpld/app/paths/Flow.h
+++ b/src/xrpld/app/paths/Flow.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_PATHS_FLOW_H_INCLUDED
-#define XRPL_APP_PATHS_FLOW_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/paths/RippleCalc.h>
 #include <xrpld/app/paths/detail/Steps.h>
@@ -52,5 +51,3 @@ flow(
     path::detail::FlowDebugInfo* flowDebugInfo = nullptr);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/paths/PathRequest.h b/src/xrpld/app/paths/PathRequest.h
index edeab4dc88..864d2cb932 100644
--- a/src/xrpld/app/paths/PathRequest.h
+++ b/src/xrpld/app/paths/PathRequest.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_PATHS_PATHREQUEST_H_INCLUDED
-#define XRPL_APP_PATHS_PATHREQUEST_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/Ledger.h>
 #include <xrpld/app/paths/Pathfinder.h>
@@ -155,5 +154,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/paths/PathRequests.h b/src/xrpld/app/paths/PathRequests.h
index 33b817f8c0..f89ca3c4da 100644
--- a/src/xrpld/app/paths/PathRequests.h
+++ b/src/xrpld/app/paths/PathRequests.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_PATHS_PATHREQUESTS_H_INCLUDED
-#define XRPL_APP_PATHS_PATHREQUESTS_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/main/Application.h>
 #include <xrpld/app/paths/PathRequest.h>
@@ -96,5 +95,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/paths/Pathfinder.h b/src/xrpld/app/paths/Pathfinder.h
index 131e9420c1..03f2d6f038 100644
--- a/src/xrpld/app/paths/Pathfinder.h
+++ b/src/xrpld/app/paths/Pathfinder.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_PATHS_PATHFINDER_H_INCLUDED
-#define XRPL_APP_PATHS_PATHFINDER_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/Ledger.h>
 #include <xrpld/app/paths/RippleLineCache.h>
@@ -211,5 +210,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/paths/RippleCalc.h b/src/xrpld/app/paths/RippleCalc.h
index 0ef2641e36..a5cecc18bf 100644
--- a/src/xrpld/app/paths/RippleCalc.h
+++ b/src/xrpld/app/paths/RippleCalc.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_PATHS_RIPPLECALC_H_INCLUDED
-#define XRPL_APP_PATHS_RIPPLECALC_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/ledger/PaymentSandbox.h>
@@ -108,5 +107,3 @@ public:
 
 }  // namespace path
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/paths/RippleLineCache.h b/src/xrpld/app/paths/RippleLineCache.h
index 8307fb8b4b..5dbdb414ee 100644
--- a/src/xrpld/app/paths/RippleLineCache.h
+++ b/src/xrpld/app/paths/RippleLineCache.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_PATHS_RIPPLELINECACHE_H_INCLUDED
-#define XRPL_APP_PATHS_RIPPLELINECACHE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/Ledger.h>
 #include <xrpld/app/paths/TrustLine.h>
@@ -99,5 +98,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/paths/TrustLine.h b/src/xrpld/app/paths/TrustLine.h
index 45cc797cb4..a0fce8847a 100644
--- a/src/xrpld/app/paths/TrustLine.h
+++ b/src/xrpld/app/paths/TrustLine.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_PATHS_RIPPLESTATE_H_INCLUDED
-#define XRPL_APP_PATHS_RIPPLESTATE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CountedObject.h>
 #include <xrpl/ledger/View.h>
@@ -217,5 +216,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/paths/detail/AmountSpec.h b/src/xrpld/app/paths/detail/AmountSpec.h
index 3ebe5fde91..690e67ae22 100644
--- a/src/xrpld/app/paths/detail/AmountSpec.h
+++ b/src/xrpld/app/paths/detail/AmountSpec.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PATH_IMPL_AMOUNTSPEC_H_INCLUDED
-#define XRPL_PATH_IMPL_AMOUNTSPEC_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/IOUAmount.h>
 #include <xrpl/protocol/STAmount.h>
@@ -197,5 +196,3 @@ toAmountSpec(EitherAmount const& ea, std::optional<Currency> const& c)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/paths/detail/FlatSets.h b/src/xrpld/app/paths/detail/FlatSets.h
index a14db370fa..a7546cc514 100644
--- a/src/xrpld/app/paths/detail/FlatSets.h
+++ b/src/xrpld/app/paths/detail/FlatSets.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_PATHS_IMPL_FLAT_SETS_H_INCLUDED
-#define XRPL_APP_PATHS_IMPL_FLAT_SETS_H_INCLUDED
+#pragma once
 
 #include <boost/container/flat_set.hpp>
 
@@ -23,5 +22,3 @@ SetUnion(boost::container::flat_set<T>& dst, boost::container::flat_set<T> const
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/paths/detail/FlowDebugInfo.h b/src/xrpld/app/paths/detail/FlowDebugInfo.h
index a38ab7864f..d7b97a49d4 100644
--- a/src/xrpld/app/paths/detail/FlowDebugInfo.h
+++ b/src/xrpld/app/paths/detail/FlowDebugInfo.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PATH_IMPL_FLOWDEBUGINFO_H_INCLUDED
-#define XRPL_PATH_IMPL_FLOWDEBUGINFO_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/paths/detail/AmountSpec.h>
 
@@ -329,4 +328,3 @@ balanceDiffsToString(std::optional<BalanceDiffs> const& bd)
 }  // namespace detail
 }  // namespace path
 }  // namespace xrpl
-#endif
diff --git a/src/xrpld/app/paths/detail/PathfinderUtils.h b/src/xrpld/app/paths/detail/PathfinderUtils.h
index 5571cd4732..560deca2d6 100644
--- a/src/xrpld/app/paths/detail/PathfinderUtils.h
+++ b/src/xrpld/app/paths/detail/PathfinderUtils.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PATH_IMPL_PATHFINDERUTILS_H_INCLUDED
-#define XRPL_PATH_IMPL_PATHFINDERUTILS_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/STAmount.h>
 
@@ -30,5 +29,3 @@ convertAllCheck(STAmount const& a)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/paths/detail/StepChecks.h b/src/xrpld/app/paths/detail/StepChecks.h
index b72461fc43..479f1298d3 100644
--- a/src/xrpld/app/paths/detail/StepChecks.h
+++ b/src/xrpld/app/paths/detail/StepChecks.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_PATHS_IMPL_STEP_CHECKS_H_INCLUDED
-#define XRPL_APP_PATHS_IMPL_STEP_CHECKS_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/beast/utility/Journal.h>
@@ -84,5 +83,3 @@ checkNoRipple(
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/paths/detail/Steps.h b/src/xrpld/app/paths/detail/Steps.h
index 7fc4d8b3b4..580b8c487e 100644
--- a/src/xrpld/app/paths/detail/Steps.h
+++ b/src/xrpld/app/paths/detail/Steps.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_PATHS_IMPL_PAYSTEPS_H_INCLUDED
-#define XRPL_APP_PATHS_IMPL_PAYSTEPS_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/paths/detail/AmountSpec.h>
 
@@ -591,5 +590,3 @@ isDirectXrpToXrp(Strand const& strand);
 /// @endcond
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/paths/detail/StrandFlow.h b/src/xrpld/app/paths/detail/StrandFlow.h
index ebb9257ed4..aa3d00a822 100644
--- a/src/xrpld/app/paths/detail/StrandFlow.h
+++ b/src/xrpld/app/paths/detail/StrandFlow.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_PATHS_IMPL_STRANDFLOW_H_INCLUDED
-#define XRPL_APP_PATHS_IMPL_STRANDFLOW_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/misc/AMMHelpers.h>
 #include <xrpld/app/paths/AMMContext.h>
@@ -784,5 +783,3 @@ flow(
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/rdb/PeerFinder.h b/src/xrpld/app/rdb/PeerFinder.h
index a6dfde1f65..2b4080255f 100644
--- a/src/xrpld/app/rdb/PeerFinder.h
+++ b/src/xrpld/app/rdb/PeerFinder.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_RDB_PEERFINDER_H_INCLUDED
-#define XRPL_APP_RDB_PEERFINDER_H_INCLUDED
+#pragma once
 
 #include <xrpld/core/Config.h>
 #include <xrpld/core/DatabaseCon.h>
@@ -43,5 +42,3 @@ void
 savePeerFinderDB(soci::session& session, std::vector<PeerFinder::Store::Entry> const& v);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/rdb/RelationalDatabase.h b/src/xrpld/app/rdb/RelationalDatabase.h
index cb43c8c95d..c0cc61f757 100644
--- a/src/xrpld/app/rdb/RelationalDatabase.h
+++ b/src/xrpld/app/rdb/RelationalDatabase.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_RDB_RELATIONALDATABASE_H_INCLUDED
-#define XRPL_APP_RDB_RELATIONALDATABASE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/Ledger.h>
 #include <xrpld/app/main/Application.h>
@@ -225,5 +224,3 @@ rangeCheckedCast(C c)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/rdb/State.h b/src/xrpld/app/rdb/State.h
index 4c68154645..52118b3cf8 100644
--- a/src/xrpld/app/rdb/State.h
+++ b/src/xrpld/app/rdb/State.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_RDB_STATE_H_INCLUDED
-#define XRPL_APP_RDB_STATE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/Ledger.h>
 #include <xrpld/app/misc/Manifest.h>
@@ -72,5 +71,3 @@ void
 setLastRotated(soci::session& session, LedgerIndex seq);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/rdb/Vacuum.h b/src/xrpld/app/rdb/Vacuum.h
index d7ca5f8bce..f592b4537e 100644
--- a/src/xrpld/app/rdb/Vacuum.h
+++ b/src/xrpld/app/rdb/Vacuum.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_RDB_VACUUM_H_INCLUDED
-#define XRPL_APP_RDB_VACUUM_H_INCLUDED
+#pragma once
 
 #include <xrpld/core/DatabaseCon.h>
 
@@ -15,5 +14,3 @@ bool
 doVacuumDB(DatabaseCon::Setup const& setup, beast::Journal j);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/rdb/Wallet.h b/src/xrpld/app/rdb/Wallet.h
index 3a967fd339..141ef53f27 100644
--- a/src/xrpld/app/rdb/Wallet.h
+++ b/src/xrpld/app/rdb/Wallet.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_RDB_WALLET_H_INCLUDED
-#define XRPL_APP_RDB_WALLET_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/misc/Manifest.h>
 #include <xrpld/core/Config.h>
@@ -145,5 +144,3 @@ void
 voteAmendment(soci::session& session, uint256 const& amendment, std::string const& name, AmendmentVote vote);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/rdb/backend/SQLiteDatabase.h b/src/xrpld/app/rdb/backend/SQLiteDatabase.h
index 6e3ec7d311..b6dcb2534b 100644
--- a/src/xrpld/app/rdb/backend/SQLiteDatabase.h
+++ b/src/xrpld/app/rdb/backend/SQLiteDatabase.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_RDB_BACKEND_SQLITEDATABASE_H_INCLUDED
-#define XRPL_APP_RDB_BACKEND_SQLITEDATABASE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/rdb/RelationalDatabase.h>
 
@@ -285,5 +284,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/rdb/backend/detail/Node.h b/src/xrpld/app/rdb/backend/detail/Node.h
index a1bfd84567..69c4894bbc 100644
--- a/src/xrpld/app/rdb/backend/detail/Node.h
+++ b/src/xrpld/app/rdb/backend/detail/Node.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_RDB_BACKEND_DETAIL_NODE_H_INCLUDED
-#define XRPL_APP_RDB_BACKEND_DETAIL_NODE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/Ledger.h>
 #include <xrpld/app/rdb/RelationalDatabase.h>
@@ -404,5 +403,3 @@ dbHasSpace(soci::session& session, Config const& config, beast::Journal j);
 
 }  // namespace detail
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/apply.h b/src/xrpld/app/tx/apply.h
index db60097200..c3ff4f905e 100644
--- a/src/xrpld/app/tx/apply.h
+++ b/src/xrpld/app/tx/apply.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_APPLY_H_INCLUDED
-#define XRPL_TX_APPLY_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/applySteps.h>
 #include <xrpld/core/Config.h>
@@ -130,5 +129,3 @@ applyTransaction(
     beast::Journal journal);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/applySteps.h b/src/xrpld/app/tx/applySteps.h
index ffb9fda5b5..ef87d352f3 100644
--- a/src/xrpld/app/tx/applySteps.h
+++ b/src/xrpld/app/tx/applySteps.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_APPLYSTEPS_H_INCLUDED
-#define XRPL_TX_APPLYSTEPS_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/Journal.h>
 #include <xrpl/ledger/ApplyViewImpl.h>
@@ -337,5 +336,3 @@ ApplyResult
 doApply(PreclaimResult const& preclaimResult, Application& app, OpenView& view);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/AMMBid.h b/src/xrpld/app/tx/detail/AMMBid.h
index b402e82f9d..83ea6e0729 100644
--- a/src/xrpld/app/tx/detail/AMMBid.h
+++ b/src/xrpld/app/tx/detail/AMMBid.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_AMMBID_H_INCLUDED
-#define XRPL_TX_AMMBID_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -66,5 +65,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif  // XRPL_TX_AMMBID_H_INCLUDED
diff --git a/src/xrpld/app/tx/detail/AMMClawback.h b/src/xrpld/app/tx/detail/AMMClawback.h
index 0615234ffa..3da3c44605 100644
--- a/src/xrpld/app/tx/detail/AMMClawback.h
+++ b/src/xrpld/app/tx/detail/AMMClawback.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_AMMCLAWBACK_H_INCLUDED
-#define XRPL_TX_AMMCLAWBACK_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -55,5 +54,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/AMMCreate.h b/src/xrpld/app/tx/detail/AMMCreate.h
index da77f79c5e..6f9fd77a2f 100644
--- a/src/xrpld/app/tx/detail/AMMCreate.h
+++ b/src/xrpld/app/tx/detail/AMMCreate.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_AMMCREATE_H_INCLUDED
-#define XRPL_TX_AMMCREATE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -62,5 +61,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif  // XRPL_TX_AMMCREATE_H_INCLUDED
diff --git a/src/xrpld/app/tx/detail/AMMDelete.h b/src/xrpld/app/tx/detail/AMMDelete.h
index a09b855c7c..20c8f87262 100644
--- a/src/xrpld/app/tx/detail/AMMDelete.h
+++ b/src/xrpld/app/tx/detail/AMMDelete.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_AMMDELETE_H_INCLUDED
-#define XRPL_TX_AMMDELETE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -34,5 +33,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif  // XRPL_TX_AMMDELETE_H_INCLUDED
diff --git a/src/xrpld/app/tx/detail/AMMDeposit.h b/src/xrpld/app/tx/detail/AMMDeposit.h
index 7fd50c4c4d..45c7995438 100644
--- a/src/xrpld/app/tx/detail/AMMDeposit.h
+++ b/src/xrpld/app/tx/detail/AMMDeposit.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_AMMDEPOSIT_H_INCLUDED
-#define XRPL_TX_AMMDEPOSIT_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -230,5 +229,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif  // XRPL_TX_AMMDEPOSIT_H_INCLUDED
diff --git a/src/xrpld/app/tx/detail/AMMVote.h b/src/xrpld/app/tx/detail/AMMVote.h
index 1dec046c29..2bc3da2301 100644
--- a/src/xrpld/app/tx/detail/AMMVote.h
+++ b/src/xrpld/app/tx/detail/AMMVote.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_AMMVOTE_H_INCLUDED
-#define XRPL_TX_AMMVOTE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -51,5 +50,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif  // XRPL_TX_AMMVOTE_H_INCLUDED
diff --git a/src/xrpld/app/tx/detail/AMMWithdraw.h b/src/xrpld/app/tx/detail/AMMWithdraw.h
index 916621a5d0..246c66100c 100644
--- a/src/xrpld/app/tx/detail/AMMWithdraw.h
+++ b/src/xrpld/app/tx/detail/AMMWithdraw.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_AMMWITHDRAW_H_INCLUDED
-#define XRPL_TX_AMMWITHDRAW_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -294,5 +293,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif  // XRPL_TX_AMMWITHDRAW_H_INCLUDED
diff --git a/src/xrpld/app/tx/detail/ApplyContext.h b/src/xrpld/app/tx/detail/ApplyContext.h
index b4e91ff76c..45345df265 100644
--- a/src/xrpld/app/tx/detail/ApplyContext.h
+++ b/src/xrpld/app/tx/detail/ApplyContext.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_APPLYCONTEXT_H_INCLUDED
-#define XRPL_TX_APPLYCONTEXT_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/main/Application.h>
 #include <xrpld/core/Config.h>
@@ -129,5 +128,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/Batch.h b/src/xrpld/app/tx/detail/Batch.h
index a8cfeadc6b..8af8b2e020 100644
--- a/src/xrpld/app/tx/detail/Batch.h
+++ b/src/xrpld/app/tx/detail/Batch.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_BATCH_H_INCLUDED
-#define XRPL_TX_BATCH_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 #include <xrpld/core/Config.h>
@@ -56,5 +55,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/BookTip.h b/src/xrpld/app/tx/detail/BookTip.h
index 51dc252835..69d3ec70d8 100644
--- a/src/xrpld/app/tx/detail/BookTip.h
+++ b/src/xrpld/app/tx/detail/BookTip.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_BOOK_BOOKTIP_H_INCLUDED
-#define XRPL_APP_BOOK_BOOKTIP_H_INCLUDED
+#pragma once
 
 #include <xrpl/ledger/View.h>
 #include <xrpl/protocol/Indexes.h>
@@ -62,5 +61,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/CancelCheck.h b/src/xrpld/app/tx/detail/CancelCheck.h
index 4be696520d..f125b9af5b 100644
--- a/src/xrpld/app/tx/detail/CancelCheck.h
+++ b/src/xrpld/app/tx/detail/CancelCheck.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_CANCELCHECK_H_INCLUDED
-#define XRPL_TX_CANCELCHECK_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -27,5 +26,3 @@ public:
 using CheckCancel = CancelCheck;
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/CancelOffer.h b/src/xrpld/app/tx/detail/CancelOffer.h
index 33af365c4d..30a7129fb4 100644
--- a/src/xrpld/app/tx/detail/CancelOffer.h
+++ b/src/xrpld/app/tx/detail/CancelOffer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_CANCELOFFER_H_INCLUDED
-#define XRPL_TX_CANCELOFFER_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -29,5 +28,3 @@ public:
 using OfferCancel = CancelOffer;
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/CashCheck.h b/src/xrpld/app/tx/detail/CashCheck.h
index f27a45a0c4..50a4f8a63a 100644
--- a/src/xrpld/app/tx/detail/CashCheck.h
+++ b/src/xrpld/app/tx/detail/CashCheck.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_CASHCHECK_H_INCLUDED
-#define XRPL_TX_CASHCHECK_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -27,5 +26,3 @@ public:
 using CheckCash = CashCheck;
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/Change.h b/src/xrpld/app/tx/detail/Change.h
index 4d7b76ed78..683b054ccb 100644
--- a/src/xrpld/app/tx/detail/Change.h
+++ b/src/xrpld/app/tx/detail/Change.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_CHANGE_H_INCLUDED
-#define XRPL_TX_CHANGE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -44,5 +43,3 @@ using SetFee = Change;
 using UNLModify = Change;
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/Clawback.h b/src/xrpld/app/tx/detail/Clawback.h
index 8db93fcc01..427edb25b4 100644
--- a/src/xrpld/app/tx/detail/Clawback.h
+++ b/src/xrpld/app/tx/detail/Clawback.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_CLAWBACK_H_INCLUDED
-#define XRPL_TX_CLAWBACK_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -28,5 +27,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/CreateCheck.h b/src/xrpld/app/tx/detail/CreateCheck.h
index ac735eecb0..b80536fe02 100644
--- a/src/xrpld/app/tx/detail/CreateCheck.h
+++ b/src/xrpld/app/tx/detail/CreateCheck.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_CREATECHECK_H_INCLUDED
-#define XRPL_TX_CREATECHECK_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -27,5 +26,3 @@ public:
 using CheckCreate = CreateCheck;
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/CreateOffer.h b/src/xrpld/app/tx/detail/CreateOffer.h
index 5aaa60c20e..14f82c501e 100644
--- a/src/xrpld/app/tx/detail/CreateOffer.h
+++ b/src/xrpld/app/tx/detail/CreateOffer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_CREATEOFFER_H_INCLUDED
-#define XRPL_TX_CREATEOFFER_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -79,5 +78,3 @@ private:
 using OfferCreate = CreateOffer;
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/CreateTicket.h b/src/xrpld/app/tx/detail/CreateTicket.h
index a41c7e2b1f..2a6e1bb8cc 100644
--- a/src/xrpld/app/tx/detail/CreateTicket.h
+++ b/src/xrpld/app/tx/detail/CreateTicket.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_CREATETICKET_H_INCLUDED
-#define XRPL_TX_CREATETICKET_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/Ledger.h>
 #include <xrpld/app/tx/detail/Transactor.h>
@@ -66,5 +65,3 @@ public:
 using TicketCreate = CreateTicket;
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/Credentials.h b/src/xrpld/app/tx/detail/Credentials.h
index 6723a2f0e4..02bccde198 100644
--- a/src/xrpld/app/tx/detail/Credentials.h
+++ b/src/xrpld/app/tx/detail/Credentials.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_CREDENTIALS_H_INCLUDED
-#define XRPL_TX_CREDENTIALS_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -76,5 +75,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/DID.h b/src/xrpld/app/tx/detail/DID.h
index b8d0889add..a00039a999 100644
--- a/src/xrpld/app/tx/detail/DID.h
+++ b/src/xrpld/app/tx/detail/DID.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_DID_H_INCLUDED
-#define XRPL_TX_DID_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -46,5 +45,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/DelegateSet.h b/src/xrpld/app/tx/detail/DelegateSet.h
index 568b16410e..2120674557 100644
--- a/src/xrpld/app/tx/detail/DelegateSet.h
+++ b/src/xrpld/app/tx/detail/DelegateSet.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_DELEGATESET_H_INCLUDED
-#define XRPL_TX_DELEGATESET_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -29,5 +28,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/DeleteAccount.h b/src/xrpld/app/tx/detail/DeleteAccount.h
index 357f87d566..742d1f4257 100644
--- a/src/xrpld/app/tx/detail/DeleteAccount.h
+++ b/src/xrpld/app/tx/detail/DeleteAccount.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_DELETEACCOUNT_H_INCLUDED
-#define XRPL_TX_DELETEACCOUNT_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -33,5 +32,3 @@ public:
 using AccountDelete = DeleteAccount;
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/DeleteOracle.h b/src/xrpld/app/tx/detail/DeleteOracle.h
index d59699cdfb..7d7cc340cb 100644
--- a/src/xrpld/app/tx/detail/DeleteOracle.h
+++ b/src/xrpld/app/tx/detail/DeleteOracle.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_DELETEORACLE_H_INCLUDED
-#define XRPL_TX_DELETEORACLE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -39,5 +38,3 @@ public:
 using OracleDelete = DeleteOracle;
 
 }  // namespace xrpl
-
-#endif  // XRPL_TX_DELETEORACLE_H_INCLUDED
diff --git a/src/xrpld/app/tx/detail/DepositPreauth.h b/src/xrpld/app/tx/detail/DepositPreauth.h
index 693b321580..f1afac3b18 100644
--- a/src/xrpld/app/tx/detail/DepositPreauth.h
+++ b/src/xrpld/app/tx/detail/DepositPreauth.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_DEPOSIT_PREAUTH_H_INCLUDED
-#define XRPL_TX_DEPOSIT_PREAUTH_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -32,5 +31,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/Escrow.h b/src/xrpld/app/tx/detail/Escrow.h
index 935fb27cd0..cb99dcae06 100644
--- a/src/xrpld/app/tx/detail/Escrow.h
+++ b/src/xrpld/app/tx/detail/Escrow.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_ESCROW_H_INCLUDED
-#define XRPL_TX_ESCROW_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -79,5 +78,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/InvariantCheck.h b/src/xrpld/app/tx/detail/InvariantCheck.h
index e941db4eff..9a20e372ba 100644
--- a/src/xrpld/app/tx/detail/InvariantCheck.h
+++ b/src/xrpld/app/tx/detail/InvariantCheck.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_TX_INVARIANTCHECK_H_INCLUDED
-#define XRPL_APP_TX_INVARIANTCHECK_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Number.h>
 #include <xrpl/basics/base_uint.h>
@@ -720,5 +719,3 @@ getInvariantChecks()
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/LedgerStateFix.h b/src/xrpld/app/tx/detail/LedgerStateFix.h
index e1a7f85ecc..66fe124cff 100644
--- a/src/xrpld/app/tx/detail/LedgerStateFix.h
+++ b/src/xrpld/app/tx/detail/LedgerStateFix.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_LEDGER_STATE_FIX_H_INCLUDED
-#define XRPL_TX_LEDGER_STATE_FIX_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -32,5 +31,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/LoanBrokerCoverClawback.h b/src/xrpld/app/tx/detail/LoanBrokerCoverClawback.h
index 3c4f997d95..139d50696a 100644
--- a/src/xrpld/app/tx/detail/LoanBrokerCoverClawback.h
+++ b/src/xrpld/app/tx/detail/LoanBrokerCoverClawback.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_LOANBROKERCOVERCLAWBACK_H_INCLUDED
-#define XRPL_TX_LOANBROKERCOVERCLAWBACK_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -30,5 +29,3 @@ public:
 //------------------------------------------------------------------------------
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/LoanBrokerCoverDeposit.h b/src/xrpld/app/tx/detail/LoanBrokerCoverDeposit.h
index d2f17b1f1c..3f683c6a62 100644
--- a/src/xrpld/app/tx/detail/LoanBrokerCoverDeposit.h
+++ b/src/xrpld/app/tx/detail/LoanBrokerCoverDeposit.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_LOANBROKERCOVERDEPOSIT_H_INCLUDED
-#define XRPL_TX_LOANBROKERCOVERDEPOSIT_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -30,5 +29,3 @@ public:
 //------------------------------------------------------------------------------
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/LoanBrokerCoverWithdraw.h b/src/xrpld/app/tx/detail/LoanBrokerCoverWithdraw.h
index e0a9a2e51b..50d0b98fa5 100644
--- a/src/xrpld/app/tx/detail/LoanBrokerCoverWithdraw.h
+++ b/src/xrpld/app/tx/detail/LoanBrokerCoverWithdraw.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_LOANBROKERCOVERWITHDRAW_H_INCLUDED
-#define XRPL_TX_LOANBROKERCOVERWITHDRAW_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -30,5 +29,3 @@ public:
 //------------------------------------------------------------------------------
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/LoanBrokerDelete.h b/src/xrpld/app/tx/detail/LoanBrokerDelete.h
index aaea2af81a..cb44277f55 100644
--- a/src/xrpld/app/tx/detail/LoanBrokerDelete.h
+++ b/src/xrpld/app/tx/detail/LoanBrokerDelete.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_LOANBROKERDELETE_H_INCLUDED
-#define XRPL_TX_LOANBROKERDELETE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -30,5 +29,3 @@ public:
 //------------------------------------------------------------------------------
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/LoanBrokerSet.h b/src/xrpld/app/tx/detail/LoanBrokerSet.h
index 57170b9cb9..cda452bebe 100644
--- a/src/xrpld/app/tx/detail/LoanBrokerSet.h
+++ b/src/xrpld/app/tx/detail/LoanBrokerSet.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_LOANBROKERSET_H_INCLUDED
-#define XRPL_TX_LOANBROKERSET_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -33,5 +32,3 @@ public:
 //------------------------------------------------------------------------------
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/LoanDelete.h b/src/xrpld/app/tx/detail/LoanDelete.h
index a1ebad340c..37889d31fb 100644
--- a/src/xrpld/app/tx/detail/LoanDelete.h
+++ b/src/xrpld/app/tx/detail/LoanDelete.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_LOANDELETE_H_INCLUDED
-#define XRPL_TX_LOANDELETE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -30,5 +29,3 @@ public:
 //------------------------------------------------------------------------------
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/LoanManage.h b/src/xrpld/app/tx/detail/LoanManage.h
index c55380d869..44b2b62b3d 100644
--- a/src/xrpld/app/tx/detail/LoanManage.h
+++ b/src/xrpld/app/tx/detail/LoanManage.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_LOANMANAGE_H_INCLUDED
-#define XRPL_TX_LOANMANAGE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -54,5 +53,3 @@ public:
 //------------------------------------------------------------------------------
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/LoanPay.h b/src/xrpld/app/tx/detail/LoanPay.h
index f951fdad5f..c947b1b6f8 100644
--- a/src/xrpld/app/tx/detail/LoanPay.h
+++ b/src/xrpld/app/tx/detail/LoanPay.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_LOANPAY_H_INCLUDED
-#define XRPL_TX_LOANPAY_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -36,5 +35,3 @@ public:
 //------------------------------------------------------------------------------
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/LoanSet.h b/src/xrpld/app/tx/detail/LoanSet.h
index d3853fbbdd..e4bb79a36d 100644
--- a/src/xrpld/app/tx/detail/LoanSet.h
+++ b/src/xrpld/app/tx/detail/LoanSet.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_LOANSET_H_INCLUDED
-#define XRPL_TX_LOANSET_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/misc/LendingHelpers.h>
 #include <xrpld/app/tx/detail/Transactor.h>
@@ -55,5 +54,3 @@ public:
 //------------------------------------------------------------------------------
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/MPTokenAuthorize.h b/src/xrpld/app/tx/detail/MPTokenAuthorize.h
index bf9a384743..c887b70fa8 100644
--- a/src/xrpld/app/tx/detail/MPTokenAuthorize.h
+++ b/src/xrpld/app/tx/detail/MPTokenAuthorize.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_MPTOKENAUTHORIZE_H_INCLUDED
-#define XRPL_TX_MPTOKENAUTHORIZE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -40,5 +39,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/MPTokenIssuanceCreate.h b/src/xrpld/app/tx/detail/MPTokenIssuanceCreate.h
index 5b5268265c..56c20ed551 100644
--- a/src/xrpld/app/tx/detail/MPTokenIssuanceCreate.h
+++ b/src/xrpld/app/tx/detail/MPTokenIssuanceCreate.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_MPTOKENISSUANCECREATE_H_INCLUDED
-#define XRPL_TX_MPTOKENISSUANCECREATE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -48,5 +47,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/MPTokenIssuanceDestroy.h b/src/xrpld/app/tx/detail/MPTokenIssuanceDestroy.h
index 5f59c9b1bd..89243944d0 100644
--- a/src/xrpld/app/tx/detail/MPTokenIssuanceDestroy.h
+++ b/src/xrpld/app/tx/detail/MPTokenIssuanceDestroy.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_MPTOKENISSUANCEDESTROY_H_INCLUDED
-#define XRPL_TX_MPTOKENISSUANCEDESTROY_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -28,5 +27,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/MPTokenIssuanceSet.h b/src/xrpld/app/tx/detail/MPTokenIssuanceSet.h
index a687a37b47..68794ca48c 100644
--- a/src/xrpld/app/tx/detail/MPTokenIssuanceSet.h
+++ b/src/xrpld/app/tx/detail/MPTokenIssuanceSet.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_MPTOKENISSUANCESET_H_INCLUDED
-#define XRPL_TX_MPTOKENISSUANCESET_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -34,5 +33,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/NFTokenAcceptOffer.h b/src/xrpld/app/tx/detail/NFTokenAcceptOffer.h
index 8eeede3d95..549c38d33b 100644
--- a/src/xrpld/app/tx/detail/NFTokenAcceptOffer.h
+++ b/src/xrpld/app/tx/detail/NFTokenAcceptOffer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_NFTOKENACCEPTOFFER_H_INCLUDED
-#define XRPL_TX_NFTOKENACCEPTOFFER_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -41,5 +40,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/NFTokenBurn.h b/src/xrpld/app/tx/detail/NFTokenBurn.h
index 5425f0902d..c2bc300ab8 100644
--- a/src/xrpld/app/tx/detail/NFTokenBurn.h
+++ b/src/xrpld/app/tx/detail/NFTokenBurn.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_BURNNFT_H_INCLUDED
-#define XRPL_TX_BURNNFT_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -25,5 +24,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/NFTokenCancelOffer.h b/src/xrpld/app/tx/detail/NFTokenCancelOffer.h
index 13a6ecc065..b1801ede25 100644
--- a/src/xrpld/app/tx/detail/NFTokenCancelOffer.h
+++ b/src/xrpld/app/tx/detail/NFTokenCancelOffer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_NFTOKENCANCELOFFER_H_INCLUDED
-#define XRPL_TX_NFTOKENCANCELOFFER_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -28,5 +27,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/NFTokenCreateOffer.h b/src/xrpld/app/tx/detail/NFTokenCreateOffer.h
index 704b253924..ed54338f49 100644
--- a/src/xrpld/app/tx/detail/NFTokenCreateOffer.h
+++ b/src/xrpld/app/tx/detail/NFTokenCreateOffer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_NFTOKENOFFERCREATE_H_INCLUDED
-#define XRPL_TX_NFTOKENOFFERCREATE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -28,5 +27,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/NFTokenMint.h b/src/xrpld/app/tx/detail/NFTokenMint.h
index a3b43b8269..52981ef467 100644
--- a/src/xrpld/app/tx/detail/NFTokenMint.h
+++ b/src/xrpld/app/tx/detail/NFTokenMint.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_NFTTOKENMINT_H_INCLUDED
-#define XRPL_TX_NFTTOKENMINT_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/NFTokenUtils.h>
 #include <xrpld/app/tx/detail/Transactor.h>
@@ -43,5 +42,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/NFTokenModify.h b/src/xrpld/app/tx/detail/NFTokenModify.h
index 4353c3d58b..f755746f1f 100644
--- a/src/xrpld/app/tx/detail/NFTokenModify.h
+++ b/src/xrpld/app/tx/detail/NFTokenModify.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_NFTOKENMODIFY_H_INCLUDED
-#define XRPL_TX_NFTOKENMODIFY_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -25,5 +24,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/NFTokenUtils.h b/src/xrpld/app/tx/detail/NFTokenUtils.h
index 97ff744d71..44d3cfb956 100644
--- a/src/xrpld/app/tx/detail/NFTokenUtils.h
+++ b/src/xrpld/app/tx/detail/NFTokenUtils.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_IMPL_DETAILS_NFTOKENUTILS_H_INCLUDED
-#define XRPL_TX_IMPL_DETAILS_NFTOKENUTILS_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -128,5 +127,3 @@ checkTrustlineDeepFrozen(ReadView const& view, AccountID const id, beast::Journa
 }  // namespace nft
 
 }  // namespace xrpl
-
-#endif  // XRPL_TX_IMPL_DETAILS_NFTOKENUTILS_H_INCLUDED
diff --git a/src/xrpld/app/tx/detail/Offer.h b/src/xrpld/app/tx/detail/Offer.h
index 7972d5dcca..7c783233f1 100644
--- a/src/xrpld/app/tx/detail/Offer.h
+++ b/src/xrpld/app/tx/detail/Offer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_BOOK_OFFER_H_INCLUDED
-#define XRPL_APP_BOOK_OFFER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/Log.h>
 #include <xrpl/basics/contract.h>
@@ -301,5 +300,3 @@ operator<<(std::ostream& os, TOffer<TIn, TOut> const& offer)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/OfferStream.h b/src/xrpld/app/tx/detail/OfferStream.h
index d7e30f018c..2f6bda3fab 100644
--- a/src/xrpld/app/tx/detail/OfferStream.h
+++ b/src/xrpld/app/tx/detail/OfferStream.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_BOOK_OFFERSTREAM_H_INCLUDED
-#define XRPL_APP_BOOK_OFFERSTREAM_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/BookTip.h>
 #include <xrpld/app/tx/detail/Offer.h>
@@ -174,5 +173,3 @@ public:
     }
 };
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/PayChan.h b/src/xrpld/app/tx/detail/PayChan.h
index f42e9549b3..8748ec9383 100644
--- a/src/xrpld/app/tx/detail/PayChan.h
+++ b/src/xrpld/app/tx/detail/PayChan.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_PAYCHAN_H_INCLUDED
-#define XRPL_TX_PAYCHAN_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -82,5 +81,3 @@ public:
 using PaymentChannelClaim = PayChanClaim;
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/Payment.h b/src/xrpld/app/tx/detail/Payment.h
index 30c9a9e326..192f2b0edb 100644
--- a/src/xrpld/app/tx/detail/Payment.h
+++ b/src/xrpld/app/tx/detail/Payment.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_PAYMENT_H_INCLUDED
-#define XRPL_TX_PAYMENT_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -43,5 +42,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/PermissionedDomainDelete.h b/src/xrpld/app/tx/detail/PermissionedDomainDelete.h
index 3ae10a739f..294fb794ae 100644
--- a/src/xrpld/app/tx/detail/PermissionedDomainDelete.h
+++ b/src/xrpld/app/tx/detail/PermissionedDomainDelete.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_PERMISSIONEDDOMAINDELETE_H_INCLUDED
-#define XRPL_TX_PERMISSIONEDDOMAINDELETE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -26,5 +25,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/PermissionedDomainSet.h b/src/xrpld/app/tx/detail/PermissionedDomainSet.h
index fde06232a5..824104e50d 100644
--- a/src/xrpld/app/tx/detail/PermissionedDomainSet.h
+++ b/src/xrpld/app/tx/detail/PermissionedDomainSet.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_PERMISSIONEDDOMAINSET_H_INCLUDED
-#define XRPL_TX_PERMISSIONEDDOMAINSET_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -29,5 +28,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/SetAccount.h b/src/xrpld/app/tx/detail/SetAccount.h
index fb8b4a0ccd..db59826347 100644
--- a/src/xrpld/app/tx/detail/SetAccount.h
+++ b/src/xrpld/app/tx/detail/SetAccount.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_SETACCOUNT_H_INCLUDED
-#define XRPL_TX_SETACCOUNT_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -38,5 +37,3 @@ public:
 using AccountSet = SetAccount;
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/SetOracle.h b/src/xrpld/app/tx/detail/SetOracle.h
index c1c9a3d3fb..6b47a5397e 100644
--- a/src/xrpld/app/tx/detail/SetOracle.h
+++ b/src/xrpld/app/tx/detail/SetOracle.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_SETORACLE_H_INCLUDED
-#define XRPL_TX_SETORACLE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -36,5 +35,3 @@ public:
 using OracleSet = SetOracle;
 
 }  // namespace xrpl
-
-#endif  // XRPL_TX_SETORACLE_H_INCLUDED
diff --git a/src/xrpld/app/tx/detail/SetRegularKey.h b/src/xrpld/app/tx/detail/SetRegularKey.h
index 735ac522fd..bc712b319a 100644
--- a/src/xrpld/app/tx/detail/SetRegularKey.h
+++ b/src/xrpld/app/tx/detail/SetRegularKey.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_SETREGULARKEY_H_INCLUDED
-#define XRPL_TX_SETREGULARKEY_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -25,5 +24,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/SetSignerList.h b/src/xrpld/app/tx/detail/SetSignerList.h
index 9fbf459728..efd8e508f9 100644
--- a/src/xrpld/app/tx/detail/SetSignerList.h
+++ b/src/xrpld/app/tx/detail/SetSignerList.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_SETSIGNERLIST_H_INCLUDED
-#define XRPL_TX_SETSIGNERLIST_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/SignerEntries.h>
 #include <xrpld/app/tx/detail/Transactor.h>
@@ -71,5 +70,3 @@ private:
 using SignerListSet = SetSignerList;
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/SetTrust.h b/src/xrpld/app/tx/detail/SetTrust.h
index b5776c6d33..1081567a66 100644
--- a/src/xrpld/app/tx/detail/SetTrust.h
+++ b/src/xrpld/app/tx/detail/SetTrust.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_SETTRUST_H_INCLUDED
-#define XRPL_TX_SETTRUST_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -35,5 +34,3 @@ public:
 using TrustSet = SetTrust;
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/SignerEntries.h b/src/xrpld/app/tx/detail/SignerEntries.h
index d4b8382ab6..fe01d6b1ee 100644
--- a/src/xrpld/app/tx/detail/SignerEntries.h
+++ b/src/xrpld/app/tx/detail/SignerEntries.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_IMPL_SIGNER_ENTRIES_H_INCLUDED
-#define XRPL_TX_IMPL_SIGNER_ENTRIES_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>  // NotTEC
 
@@ -64,5 +63,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif  // XRPL_TX_IMPL_SIGNER_ENTRIES_H_INCLUDED
diff --git a/src/xrpld/app/tx/detail/Transactor.h b/src/xrpld/app/tx/detail/Transactor.h
index 13c0a39201..e06086a55d 100644
--- a/src/xrpld/app/tx/detail/Transactor.h
+++ b/src/xrpld/app/tx/detail/Transactor.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_TX_TRANSACTOR_H_INCLUDED
-#define XRPL_APP_TX_TRANSACTOR_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/applySteps.h>
 #include <xrpld/app/tx/detail/ApplyContext.h>
@@ -419,5 +418,3 @@ Transactor::validNumericMinimum(std::optional<T> value, unit::ValueUnit<Unit, T>
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/VaultClawback.h b/src/xrpld/app/tx/detail/VaultClawback.h
index d05f280e75..c93289e641 100644
--- a/src/xrpld/app/tx/detail/VaultClawback.h
+++ b/src/xrpld/app/tx/detail/VaultClawback.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_VAULTCLAWBACK_H_INCLUDED
-#define XRPL_TX_VAULTCLAWBACK_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -33,5 +32,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/VaultCreate.h b/src/xrpld/app/tx/detail/VaultCreate.h
index 78593eb491..20b18f5cc2 100644
--- a/src/xrpld/app/tx/detail/VaultCreate.h
+++ b/src/xrpld/app/tx/detail/VaultCreate.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_VAULTCREATE_H_INCLUDED
-#define XRPL_TX_VAULTCREATE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -31,5 +30,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/VaultDelete.h b/src/xrpld/app/tx/detail/VaultDelete.h
index e7c71b408c..8d1f214885 100644
--- a/src/xrpld/app/tx/detail/VaultDelete.h
+++ b/src/xrpld/app/tx/detail/VaultDelete.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_VAULTDELETE_H_INCLUDED
-#define XRPL_TX_VAULTDELETE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -25,5 +24,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/VaultDeposit.h b/src/xrpld/app/tx/detail/VaultDeposit.h
index 1fd62b95ff..6c63308407 100644
--- a/src/xrpld/app/tx/detail/VaultDeposit.h
+++ b/src/xrpld/app/tx/detail/VaultDeposit.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_VAULTDEPOSIT_H_INCLUDED
-#define XRPL_TX_VAULTDEPOSIT_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -25,5 +24,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/VaultSet.h b/src/xrpld/app/tx/detail/VaultSet.h
index bfa38e5284..1e8a15291e 100644
--- a/src/xrpld/app/tx/detail/VaultSet.h
+++ b/src/xrpld/app/tx/detail/VaultSet.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_VAULTSET_H_INCLUDED
-#define XRPL_TX_VAULTSET_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -28,5 +27,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/VaultWithdraw.h b/src/xrpld/app/tx/detail/VaultWithdraw.h
index 33463831e5..f832c206f8 100644
--- a/src/xrpld/app/tx/detail/VaultWithdraw.h
+++ b/src/xrpld/app/tx/detail/VaultWithdraw.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_VAULTWITHDRAW_H_INCLUDED
-#define XRPL_TX_VAULTWITHDRAW_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -25,5 +24,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/app/tx/detail/XChainBridge.h b/src/xrpld/app/tx/detail/XChainBridge.h
index 0c39cbb690..3d0c250f24 100644
--- a/src/xrpld/app/tx/detail/XChainBridge.h
+++ b/src/xrpld/app/tx/detail/XChainBridge.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_TX_XCHAINBRIDGE_H_INCLUDED
-#define XRPL_TX_XCHAINBRIDGE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/tx/detail/Transactor.h>
 
@@ -239,5 +238,3 @@ using XChainAccountCreateCommit = XChainCreateAccountCommit;
 //------------------------------------------------------------------------------
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/conditions/Condition.h b/src/xrpld/conditions/Condition.h
index 55a6fc1e7c..50872e75ef 100644
--- a/src/xrpld/conditions/Condition.h
+++ b/src/xrpld/conditions/Condition.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CONDITIONS_CONDITION_H
-#define XRPL_CONDITIONS_CONDITION_H
+#pragma once
 
 #include <xrpld/conditions/detail/utils.h>
 
@@ -93,5 +92,3 @@ operator!=(Condition const& lhs, Condition const& rhs)
 }  // namespace cryptoconditions
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/conditions/Fulfillment.h b/src/xrpld/conditions/Fulfillment.h
index 5d31fd64ac..840e9f9993 100644
--- a/src/xrpld/conditions/Fulfillment.h
+++ b/src/xrpld/conditions/Fulfillment.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CONDITIONS_FULFILLMENT_H
-#define XRPL_CONDITIONS_FULFILLMENT_H
+#pragma once
 
 #include <xrpld/conditions/Condition.h>
 
@@ -122,5 +121,3 @@ validate(Fulfillment const& f, Condition const& c);
 
 }  // namespace cryptoconditions
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/conditions/detail/PreimageSha256.h b/src/xrpld/conditions/detail/PreimageSha256.h
index f495885794..f3ce1a03e0 100644
--- a/src/xrpld/conditions/detail/PreimageSha256.h
+++ b/src/xrpld/conditions/detail/PreimageSha256.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CONDITIONS_PREIMAGE_SHA256_H
-#define XRPL_CONDITIONS_PREIMAGE_SHA256_H
+#pragma once
 
 #include <xrpld/conditions/Condition.h>
 #include <xrpld/conditions/Fulfillment.h>
@@ -131,5 +130,3 @@ public:
 
 }  // namespace cryptoconditions
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/conditions/detail/error.h b/src/xrpld/conditions/detail/error.h
index 65584e974a..fdeed3d9ac 100644
--- a/src/xrpld/conditions/detail/error.h
+++ b/src/xrpld/conditions/detail/error.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CONDITIONS_ERROR_H
-#define XRPL_CONDITIONS_ERROR_H
+#pragma once
 
 #include <system_error>
 
@@ -43,5 +42,3 @@ struct is_error_code_enum<xrpl::cryptoconditions::error>
 };
 
 }  // namespace std
-
-#endif
diff --git a/src/xrpld/conditions/detail/utils.h b/src/xrpld/conditions/detail/utils.h
index b07b7b29e0..2a4187718b 100644
--- a/src/xrpld/conditions/detail/utils.h
+++ b/src/xrpld/conditions/detail/utils.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CONDITIONS_UTILS_H
-#define XRPL_CONDITIONS_UTILS_H
+#pragma once
 
 #include <xrpld/conditions/detail/error.h>
 
@@ -209,5 +208,3 @@ parseInteger(Slice& s, std::size_t count, std::error_code& ec)
 }  // namespace der
 }  // namespace cryptoconditions
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/consensus/Consensus.h b/src/xrpld/consensus/Consensus.h
index cdff9aa5ac..e02ec927a4 100644
--- a/src/xrpld/consensus/Consensus.h
+++ b/src/xrpld/consensus/Consensus.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CONSENSUS_CONSENSUS_H_INCLUDED
-#define XRPL_CONSENSUS_CONSENSUS_H_INCLUDED
+#pragma once
 
 #include <xrpld/consensus/ConsensusParms.h>
 #include <xrpld/consensus/ConsensusProposal.h>
@@ -1774,5 +1773,3 @@ Consensus<Adaptor>::asCloseTime(NetClock::time_point raw) const
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/consensus/ConsensusParms.h b/src/xrpld/consensus/ConsensusParms.h
index 94e0d16f27..8839b95c8b 100644
--- a/src/xrpld/consensus/ConsensusParms.h
+++ b/src/xrpld/consensus/ConsensusParms.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CONSENSUS_CONSENSUS_PARMS_H_INCLUDED
-#define XRPL_CONSENSUS_CONSENSUS_PARMS_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/instrumentation.h>
 
@@ -174,4 +173,3 @@ getNeededWeight(
 }
 
 }  // namespace xrpl
-#endif
diff --git a/src/xrpld/consensus/ConsensusProposal.h b/src/xrpld/consensus/ConsensusProposal.h
index b91af6832a..f2b891cdd6 100644
--- a/src/xrpld/consensus/ConsensusProposal.h
+++ b/src/xrpld/consensus/ConsensusProposal.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CONSENSUS_CONSENSUSPROPOSAL_H_INCLUDED
-#define XRPL_CONSENSUS_CONSENSUSPROPOSAL_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/base_uint.h>
 #include <xrpl/basics/chrono.h>
@@ -256,4 +255,3 @@ operator==(
         a.position() == b.position() && a.closeTime() == b.closeTime() && a.seenTime() == b.seenTime();
 }
 }  // namespace xrpl
-#endif
diff --git a/src/xrpld/consensus/ConsensusTypes.h b/src/xrpld/consensus/ConsensusTypes.h
index f54e11228b..2331c9dfbf 100644
--- a/src/xrpld/consensus/ConsensusTypes.h
+++ b/src/xrpld/consensus/ConsensusTypes.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CONSENSUS_CONSENSUS_TYPES_H_INCLUDED
-#define XRPL_CONSENSUS_CONSENSUS_TYPES_H_INCLUDED
+#pragma once
 
 #include <xrpld/consensus/ConsensusProposal.h>
 #include <xrpld/consensus/DisputedTx.h>
@@ -220,5 +219,3 @@ struct ConsensusResult
     std::size_t proposers = 0;
 };
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/consensus/DisputedTx.h b/src/xrpld/consensus/DisputedTx.h
index 44e9f94793..a1e8d84fa3 100644
--- a/src/xrpld/consensus/DisputedTx.h
+++ b/src/xrpld/consensus/DisputedTx.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_CONSENSUS_IMPL_DISPUTEDTX_H_INCLUDED
-#define XRPL_APP_CONSENSUS_IMPL_DISPUTEDTX_H_INCLUDED
+#pragma once
 
 #include <xrpld/consensus/ConsensusParms.h>
 
@@ -327,5 +326,3 @@ DisputedTx<Tx_t, NodeID_t>::getJson() const
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/consensus/LedgerTiming.h b/src/xrpld/consensus/LedgerTiming.h
index 7bca012460..416c3bc165 100644
--- a/src/xrpld/consensus/LedgerTiming.h
+++ b/src/xrpld/consensus/LedgerTiming.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_LEDGER_LEDGERTIMING_H_INCLUDED
-#define XRPL_APP_LEDGER_LEDGERTIMING_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/chrono.h>
 #include <xrpl/beast/utility/Journal.h>
@@ -137,4 +136,3 @@ effCloseTime(
 }
 
 }  // namespace xrpl
-#endif
diff --git a/src/xrpld/consensus/LedgerTrie.h b/src/xrpld/consensus/LedgerTrie.h
index b823079a8b..e5f9f1ce2d 100644
--- a/src/xrpld/consensus/LedgerTrie.h
+++ b/src/xrpld/consensus/LedgerTrie.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_CONSENSUS_LEDGERS_TRIE_H_INCLUDED
-#define XRPL_APP_CONSENSUS_LEDGERS_TRIE_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/ToString.h>
 #include <xrpl/beast/utility/instrumentation.h>
@@ -809,4 +808,3 @@ public:
 };
 
 }  // namespace xrpl
-#endif
diff --git a/src/xrpld/consensus/Validations.h b/src/xrpld/consensus/Validations.h
index 6de74b4f4d..92892ff1f6 100644
--- a/src/xrpld/consensus/Validations.h
+++ b/src/xrpld/consensus/Validations.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CONSENSUS_VALIDATIONS_H_INCLUDED
-#define XRPL_CONSENSUS_VALIDATIONS_H_INCLUDED
+#pragma once
 
 #include <xrpld/consensus/LedgerTrie.h>
 
@@ -1093,4 +1092,3 @@ public:
 };
 
 }  // namespace xrpl
-#endif
diff --git a/src/xrpld/core/Config.h b/src/xrpld/core/Config.h
index e2e16bcd98..86b663a212 100644
--- a/src/xrpld/core/Config.h
+++ b/src/xrpld/core/Config.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CORE_CONFIG_H_INCLUDED
-#define XRPL_CORE_CONFIG_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/BasicConfig.h>
 #include <xrpl/basics/base_uint.h>
@@ -357,5 +356,3 @@ FeeSetup
 setup_FeeVote(Section const& section);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/core/ConfigSections.h b/src/xrpld/core/ConfigSections.h
index 6f8a13a145..7f22dd59c1 100644
--- a/src/xrpld/core/ConfigSections.h
+++ b/src/xrpld/core/ConfigSections.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CORE_CONFIGSECTIONS_H_INCLUDED
-#define XRPL_CORE_CONFIGSECTIONS_H_INCLUDED
+#pragma once
 
 #include <string>
 
@@ -79,5 +78,3 @@ struct ConfigSection
 #define SECTION_WORKERS "workers"
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/core/DatabaseCon.h b/src/xrpld/core/DatabaseCon.h
index 854cfc827f..89d582257b 100644
--- a/src/xrpld/core/DatabaseCon.h
+++ b/src/xrpld/core/DatabaseCon.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_DATA_DATABASECON_H_INCLUDED
-#define XRPL_APP_DATA_DATABASECON_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/main/DBInit.h>
 #include <xrpld/core/Config.h>
@@ -234,5 +233,3 @@ DatabaseCon::Setup
 setup_DatabaseCon(Config const& c, std::optional<beast::Journal> j = std::nullopt);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/core/SociDB.h b/src/xrpld/core/SociDB.h
index b5b6db92bc..acfc183076 100644
--- a/src/xrpld/core/SociDB.h
+++ b/src/xrpld/core/SociDB.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SOCIDB_H_INCLUDED
-#define XRPL_SOCIDB_H_INCLUDED
+#pragma once
 
 /** An embedded database wrapper with an intuitive, type-safe interface.
 
@@ -119,5 +118,3 @@ makeCheckpointer(std::uintptr_t id, std::weak_ptr<soci::session>, JobQueue&, Log
 #if defined(__clang__)
 #pragma clang diagnostic pop
 #endif
-
-#endif
diff --git a/src/xrpld/core/TimeKeeper.h b/src/xrpld/core/TimeKeeper.h
index 8c04d0a625..bb6ab3ec23 100644
--- a/src/xrpld/core/TimeKeeper.h
+++ b/src/xrpld/core/TimeKeeper.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_CORE_TIMEKEEPER_H_INCLUDED
-#define XRPL_CORE_TIMEKEEPER_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/chrono.h>
 #include <xrpl/beast/clock/abstract_clock.h>
@@ -97,5 +96,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/overlay/Cluster.h b/src/xrpld/overlay/Cluster.h
index 30627f90ae..7783d96100 100644
--- a/src/xrpld/overlay/Cluster.h
+++ b/src/xrpld/overlay/Cluster.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_OVERLAY_CLUSTER_H_INCLUDED
-#define XRPL_OVERLAY_CLUSTER_H_INCLUDED
+#pragma once
 
 #include <xrpld/overlay/ClusterNode.h>
 
@@ -95,5 +94,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/overlay/ClusterNode.h b/src/xrpld/overlay/ClusterNode.h
index 03c294c736..c6ab208383 100644
--- a/src/xrpld/overlay/ClusterNode.h
+++ b/src/xrpld/overlay/ClusterNode.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_PEERS_CLUSTERNODESTATUS_H_INCLUDED
-#define XRPL_APP_PEERS_CLUSTERNODESTATUS_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/chrono.h>
 #include <xrpl/protocol/PublicKey.h>
@@ -55,5 +54,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/overlay/Compression.h b/src/xrpld/overlay/Compression.h
index b13a0a8661..2bfc366e30 100644
--- a/src/xrpld/overlay/Compression.h
+++ b/src/xrpld/overlay/Compression.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_COMPRESSION_H_INCLUDED
-#define XRPL_COMPRESSION_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/CompressionAlgorithms.h>
 #include <xrpl/basics/Log.h>
@@ -89,5 +88,3 @@ compress(void const* in, std::size_t inSize, BufferFactory&& bf, Algorithm algor
 }  // namespace compression
 
 }  // namespace xrpl
-
-#endif  // XRPL_COMPRESSION_H_INCLUDED
diff --git a/src/xrpld/overlay/Message.h b/src/xrpld/overlay/Message.h
index 550c24eef3..30650d384c 100644
--- a/src/xrpld/overlay/Message.h
+++ b/src/xrpld/overlay/Message.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_OVERLAY_MESSAGE_H_INCLUDED
-#define XRPL_OVERLAY_MESSAGE_H_INCLUDED
+#pragma once
 
 #include <xrpld/overlay/Compression.h>
 
@@ -118,5 +117,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/overlay/Overlay.h b/src/xrpld/overlay/Overlay.h
index 7642614232..f1d1104d4e 100644
--- a/src/xrpld/overlay/Overlay.h
+++ b/src/xrpld/overlay/Overlay.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_OVERLAY_OVERLAY_H_INCLUDED
-#define XRPL_OVERLAY_OVERLAY_H_INCLUDED
+#pragma once
 
 #include <xrpld/overlay/Peer.h>
 
@@ -210,5 +209,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/overlay/Peer.h b/src/xrpld/overlay/Peer.h
index 35feb05271..a0e4c040fd 100644
--- a/src/xrpld/overlay/Peer.h
+++ b/src/xrpld/overlay/Peer.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_OVERLAY_PEER_H_INCLUDED
-#define XRPL_OVERLAY_PEER_H_INCLUDED
+#pragma once
 
 #include <xrpld/overlay/Message.h>
 
@@ -120,5 +119,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/overlay/PeerReservationTable.h b/src/xrpld/overlay/PeerReservationTable.h
index 7c66ad6e2d..8f187bf324 100644
--- a/src/xrpld/overlay/PeerReservationTable.h
+++ b/src/xrpld/overlay/PeerReservationTable.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_OVERLAY_PEER_RESERVATION_TABLE_H_INCLUDED
-#define XRPL_OVERLAY_PEER_RESERVATION_TABLE_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/hash/hash_append.h>
 #include <xrpl/beast/hash/uhash.h>
@@ -97,5 +96,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/overlay/PeerSet.h b/src/xrpld/overlay/PeerSet.h
index 850ba21c53..b69d139b4f 100644
--- a/src/xrpld/overlay/PeerSet.h
+++ b/src/xrpld/overlay/PeerSet.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_APP_PEERS_PEERSET_H_INCLUDED
-#define XRPL_APP_PEERS_PEERSET_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/main/Application.h>
 #include <xrpld/overlay/Peer.h>
@@ -74,5 +73,3 @@ std::unique_ptr<PeerSet>
 make_DummyPeerSet(Application& app);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/overlay/ReduceRelayCommon.h b/src/xrpld/overlay/ReduceRelayCommon.h
index 990e4b51d2..9ddde335e6 100644
--- a/src/xrpld/overlay/ReduceRelayCommon.h
+++ b/src/xrpld/overlay/ReduceRelayCommon.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_OVERLAY_REDUCERELAYCOMMON_H_INCLUDED
-#define XRPL_OVERLAY_REDUCERELAYCOMMON_H_INCLUDED
+#pragma once
 
 #include <chrono>
 
@@ -42,5 +41,3 @@ static constexpr std::size_t MAX_TX_QUEUE_SIZE = 10000;
 }  // namespace reduce_relay
 
 }  // namespace xrpl
-
-#endif  // XRPL_REDUCERELAYCOMMON_H_INCLUDED
diff --git a/src/xrpld/overlay/Slot.h b/src/xrpld/overlay/Slot.h
index db2ff69910..f3fd919648 100644
--- a/src/xrpld/overlay/Slot.h
+++ b/src/xrpld/overlay/Slot.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_OVERLAY_SLOT_H_INCLUDED
-#define XRPL_OVERLAY_SLOT_H_INCLUDED
+#pragma once
 
 #include <xrpld/core/Config.h>
 #include <xrpld/overlay/Peer.h>
@@ -765,5 +764,3 @@ Slots<clock_type>::deleteIdlePeers()
 }  // namespace reduce_relay
 
 }  // namespace xrpl
-
-#endif  // XRPL_OVERLAY_SLOT_H_INCLUDED
diff --git a/src/xrpld/overlay/Squelch.h b/src/xrpld/overlay/Squelch.h
index a225f39998..cca5dfeff1 100644
--- a/src/xrpld/overlay/Squelch.h
+++ b/src/xrpld/overlay/Squelch.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_OVERLAY_SQUELCH_H_INCLUDED
-#define XRPL_OVERLAY_SQUELCH_H_INCLUDED
+#pragma once
 
 #include <xrpld/overlay/ReduceRelayCommon.h>
 
@@ -100,5 +99,3 @@ Squelch<clock_type>::expireSquelch(PublicKey const& validator)
 }  // namespace reduce_relay
 
 }  // namespace xrpl
-
-#endif  // XRPL_SQUELCH_H
diff --git a/src/xrpld/overlay/detail/ConnectAttempt.h b/src/xrpld/overlay/detail/ConnectAttempt.h
index e750541561..4cd8c357db 100644
--- a/src/xrpld/overlay/detail/ConnectAttempt.h
+++ b/src/xrpld/overlay/detail/ConnectAttempt.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_OVERLAY_CONNECTATTEMPT_H_INCLUDED
-#define XRPL_OVERLAY_CONNECTATTEMPT_H_INCLUDED
+#pragma once
 
 #include <xrpld/overlay/detail/OverlayImpl.h>
 
@@ -270,5 +269,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/overlay/detail/Handshake.h b/src/xrpld/overlay/detail/Handshake.h
index 7e1ba07fca..4a8e81d6f9 100644
--- a/src/xrpld/overlay/detail/Handshake.h
+++ b/src/xrpld/overlay/detail/Handshake.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_OVERLAY_HANDSHAKE_H_INCLUDED
-#define XRPL_OVERLAY_HANDSHAKE_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/main/Application.h>
 #include <xrpld/overlay/detail/ProtocolVersion.h>
@@ -217,5 +216,3 @@ makeFeaturesResponseHeader(
     bool vpReduceRelayEnabled);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/overlay/detail/OverlayImpl.h b/src/xrpld/overlay/detail/OverlayImpl.h
index 03b3b31da0..19fff6a29a 100644
--- a/src/xrpld/overlay/detail/OverlayImpl.h
+++ b/src/xrpld/overlay/detail/OverlayImpl.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_OVERLAY_OVERLAYIMPL_H_INCLUDED
-#define XRPL_OVERLAY_OVERLAYIMPL_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/main/Application.h>
 #include <xrpld/overlay/Message.h>
@@ -592,5 +591,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/overlay/detail/PeerImp.h b/src/xrpld/overlay/detail/PeerImp.h
index 3b6cfe4b4b..65a6112159 100644
--- a/src/xrpld/overlay/detail/PeerImp.h
+++ b/src/xrpld/overlay/detail/PeerImp.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_OVERLAY_PEERIMP_H_INCLUDED
-#define XRPL_OVERLAY_PEERIMP_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/consensus/RCLCxPeerPos.h>
 #include <xrpld/app/ledger/detail/LedgerReplayMsgHandler.h>
@@ -864,5 +863,3 @@ PeerImp::sendEndpoints(FwdIt first, FwdIt last)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/overlay/detail/ProtocolMessage.h b/src/xrpld/overlay/detail/ProtocolMessage.h
index 03514b6d60..9a0e63744d 100644
--- a/src/xrpld/overlay/detail/ProtocolMessage.h
+++ b/src/xrpld/overlay/detail/ProtocolMessage.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_OVERLAY_PROTOCOLMESSAGE_H_INCLUDED
-#define XRPL_OVERLAY_PROTOCOLMESSAGE_H_INCLUDED
+#pragma once
 
 #include <xrpld/overlay/Compression.h>
 #include <xrpld/overlay/Message.h>
@@ -424,5 +423,3 @@ invokeProtocolMessage(Buffers const& buffers, Handler& handler, std::size_t& hin
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/overlay/detail/ProtocolVersion.h b/src/xrpld/overlay/detail/ProtocolVersion.h
index 9499cd1c1b..5b3a1b3302 100644
--- a/src/xrpld/overlay/detail/ProtocolVersion.h
+++ b/src/xrpld/overlay/detail/ProtocolVersion.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_OVERLAY_PROTOCOLVERSION_H_INCLUDED
-#define XRPL_OVERLAY_PROTOCOLVERSION_H_INCLUDED
+#pragma once
 
 #include <boost/beast/core/string.hpp>
 
@@ -59,5 +58,3 @@ bool
 isProtocolSupported(ProtocolVersion const& v);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/overlay/detail/TrafficCount.h b/src/xrpld/overlay/detail/TrafficCount.h
index f760c6076e..bb9f5686e6 100644
--- a/src/xrpld/overlay/detail/TrafficCount.h
+++ b/src/xrpld/overlay/detail/TrafficCount.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_OVERLAY_TRAFFIC_H_INCLUDED
-#define XRPL_OVERLAY_TRAFFIC_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/protocol/messages.h>
@@ -350,4 +349,3 @@ protected:
 };
 
 }  // namespace xrpl
-#endif
diff --git a/src/xrpld/overlay/detail/Tuning.h b/src/xrpld/overlay/detail/Tuning.h
index c18d17c359..bd62cd2a03 100644
--- a/src/xrpld/overlay/detail/Tuning.h
+++ b/src/xrpld/overlay/detail/Tuning.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_OVERLAY_TUNING_H_INCLUDED
-#define XRPL_OVERLAY_TUNING_H_INCLUDED
+#pragma once
 
 #include <chrono>
 
@@ -48,5 +47,3 @@ std::size_t constexpr readBufferBytes = 16384;
 }  // namespace Tuning
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/overlay/detail/TxMetrics.h b/src/xrpld/overlay/detail/TxMetrics.h
index 5bbf1a9731..37194c34e3 100644
--- a/src/xrpld/overlay/detail/TxMetrics.h
+++ b/src/xrpld/overlay/detail/TxMetrics.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_OVERLAY_TXMETRICS_H_INCLUDED
-#define XRPL_OVERLAY_TXMETRICS_H_INCLUDED
+#pragma once
 
 #include <xrpl/json/json_value.h>
 #include <xrpl/protocol/messages.h>
@@ -115,5 +114,3 @@ struct TxMetrics
 }  // namespace metrics
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/overlay/detail/ZeroCopyStream.h b/src/xrpld/overlay/detail/ZeroCopyStream.h
index ac814ebbad..112217b737 100644
--- a/src/xrpld/overlay/detail/ZeroCopyStream.h
+++ b/src/xrpld/overlay/detail/ZeroCopyStream.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_OVERLAY_ZEROCOPYSTREAM_H_INCLUDED
-#define XRPL_OVERLAY_ZEROCOPYSTREAM_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/instrumentation.h>
 
@@ -188,5 +187,3 @@ ZeroCopyOutputStream<Streambuf>::BackUp(int count)
 }
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/overlay/make_Overlay.h b/src/xrpld/overlay/make_Overlay.h
index 6c37c1c825..936d3abc0f 100644
--- a/src/xrpld/overlay/make_Overlay.h
+++ b/src/xrpld/overlay/make_Overlay.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_OVERLAY_MAKE_OVERLAY_H_INCLUDED
-#define XRPL_OVERLAY_MAKE_OVERLAY_H_INCLUDED
+#pragma once
 
 #include <xrpld/overlay/Overlay.h>
 #include <xrpld/rpc/ServerHandler.h>
@@ -26,5 +25,3 @@ make_Overlay(
     beast::insight::Collector::ptr const& collector);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/overlay/predicates.h b/src/xrpld/overlay/predicates.h
index 7b7baa0a8a..3adecf7c6a 100644
--- a/src/xrpld/overlay/predicates.h
+++ b/src/xrpld/overlay/predicates.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_OVERLAY_PREDICATES_H_INCLUDED
-#define XRPL_OVERLAY_PREDICATES_H_INCLUDED
+#pragma once
 
 #include <xrpld/overlay/Message.h>
 #include <xrpld/overlay/Peer.h>
@@ -155,5 +154,3 @@ struct peer_in_set
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/peerfinder/PeerfinderManager.h b/src/xrpld/peerfinder/PeerfinderManager.h
index 098702d2d3..ca82c0bdf9 100644
--- a/src/xrpld/peerfinder/PeerfinderManager.h
+++ b/src/xrpld/peerfinder/PeerfinderManager.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PEERFINDER_MANAGER_H_INCLUDED
-#define XRPL_PEERFINDER_MANAGER_H_INCLUDED
+#pragma once
 
 #include <xrpld/core/Config.h>
 #include <xrpld/peerfinder/Slot.h>
@@ -281,5 +280,3 @@ public:
 
 }  // namespace PeerFinder
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/peerfinder/Slot.h b/src/xrpld/peerfinder/Slot.h
index 1d5d58884a..d0fce0626d 100644
--- a/src/xrpld/peerfinder/Slot.h
+++ b/src/xrpld/peerfinder/Slot.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PEERFINDER_SLOT_H_INCLUDED
-#define XRPL_PEERFINDER_SLOT_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/net/IPEndpoint.h>
 #include <xrpl/protocol/PublicKey.h>
@@ -61,5 +60,3 @@ public:
 
 }  // namespace PeerFinder
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/peerfinder/detail/Bootcache.h b/src/xrpld/peerfinder/detail/Bootcache.h
index 8aa2feaf88..8517bde049 100644
--- a/src/xrpld/peerfinder/detail/Bootcache.h
+++ b/src/xrpld/peerfinder/detail/Bootcache.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PEERFINDER_BOOTCACHE_H_INCLUDED
-#define XRPL_PEERFINDER_BOOTCACHE_H_INCLUDED
+#pragma once
 
 #include <xrpld/peerfinder/PeerfinderManager.h>
 #include <xrpld/peerfinder/detail/Store.h>
@@ -172,5 +171,3 @@ private:
 
 }  // namespace PeerFinder
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/peerfinder/detail/Checker.h b/src/xrpld/peerfinder/detail/Checker.h
index b0c38693ed..42987f3ec0 100644
--- a/src/xrpld/peerfinder/detail/Checker.h
+++ b/src/xrpld/peerfinder/detail/Checker.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PEERFINDER_CHECKER_H_INCLUDED
-#define XRPL_PEERFINDER_CHECKER_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/net/IPAddressConversion.h>
 
@@ -196,5 +195,3 @@ Checker<Protocol>::remove(basic_async_op& op)
 
 }  // namespace PeerFinder
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/peerfinder/detail/Counts.h b/src/xrpld/peerfinder/detail/Counts.h
index 15ae42fcbb..3d687711d1 100644
--- a/src/xrpld/peerfinder/detail/Counts.h
+++ b/src/xrpld/peerfinder/detail/Counts.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PEERFINDER_COUNTS_H_INCLUDED
-#define XRPL_PEERFINDER_COUNTS_H_INCLUDED
+#pragma once
 
 #include <xrpld/peerfinder/PeerfinderManager.h>
 #include <xrpld/peerfinder/Slot.h>
@@ -319,5 +318,3 @@ private:
 
 }  // namespace PeerFinder
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/peerfinder/detail/Fixed.h b/src/xrpld/peerfinder/detail/Fixed.h
index 007ee1698d..75b5ed9062 100644
--- a/src/xrpld/peerfinder/detail/Fixed.h
+++ b/src/xrpld/peerfinder/detail/Fixed.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PEERFINDER_FIXED_H_INCLUDED
-#define XRPL_PEERFINDER_FIXED_H_INCLUDED
+#pragma once
 
 #include <xrpld/peerfinder/detail/Tuning.h>
 
@@ -46,5 +45,3 @@ private:
 
 }  // namespace PeerFinder
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/peerfinder/detail/Handouts.h b/src/xrpld/peerfinder/detail/Handouts.h
index 85cce2fef3..afc2bddb40 100644
--- a/src/xrpld/peerfinder/detail/Handouts.h
+++ b/src/xrpld/peerfinder/detail/Handouts.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PEERFINDER_HANDOUTS_H_INCLUDED
-#define XRPL_PEERFINDER_HANDOUTS_H_INCLUDED
+#pragma once
 
 #include <xrpld/peerfinder/detail/SlotImp.h>
 #include <xrpld/peerfinder/detail/Tuning.h>
@@ -331,5 +330,3 @@ ConnectHandouts::try_insert(beast::IP::Endpoint const& endpoint)
 
 }  // namespace PeerFinder
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/peerfinder/detail/Livecache.h b/src/xrpld/peerfinder/detail/Livecache.h
index c4052967ab..548db4e34e 100644
--- a/src/xrpld/peerfinder/detail/Livecache.h
+++ b/src/xrpld/peerfinder/detail/Livecache.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PEERFINDER_LIVECACHE_H_INCLUDED
-#define XRPL_PEERFINDER_LIVECACHE_H_INCLUDED
+#pragma once
 
 #include <xrpld/peerfinder/PeerfinderManager.h>
 #include <xrpld/peerfinder/detail/Tuning.h>
@@ -513,5 +512,3 @@ Livecache<Allocator>::hops_t::remove(Element& e)
 
 }  // namespace PeerFinder
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/peerfinder/detail/Logic.h b/src/xrpld/peerfinder/detail/Logic.h
index f437a7c3a7..7e2b4f0015 100644
--- a/src/xrpld/peerfinder/detail/Logic.h
+++ b/src/xrpld/peerfinder/detail/Logic.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PEERFINDER_LOGIC_H_INCLUDED
-#define XRPL_PEERFINDER_LOGIC_H_INCLUDED
+#pragma once
 
 #include <xrpld/peerfinder/PeerfinderManager.h>
 #include <xrpld/peerfinder/detail/Bootcache.h>
@@ -1168,5 +1167,3 @@ Logic<Checker>::onRedirects(FwdIter first, FwdIter last, boost::asio::ip::tcp::e
 
 }  // namespace PeerFinder
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/peerfinder/detail/SlotImp.h b/src/xrpld/peerfinder/detail/SlotImp.h
index bcfd968228..f18410d214 100644
--- a/src/xrpld/peerfinder/detail/SlotImp.h
+++ b/src/xrpld/peerfinder/detail/SlotImp.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PEERFINDER_SLOTIMP_H_INCLUDED
-#define XRPL_PEERFINDER_SLOTIMP_H_INCLUDED
+#pragma once
 
 #include <xrpld/peerfinder/PeerfinderManager.h>
 #include <xrpld/peerfinder/Slot.h>
@@ -193,5 +192,3 @@ public:
 
 }  // namespace PeerFinder
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/peerfinder/detail/Source.h b/src/xrpld/peerfinder/detail/Source.h
index 1fe33e053a..8fc97b639f 100644
--- a/src/xrpld/peerfinder/detail/Source.h
+++ b/src/xrpld/peerfinder/detail/Source.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PEERFINDER_SOURCE_H_INCLUDED
-#define XRPL_PEERFINDER_SOURCE_H_INCLUDED
+#pragma once
 
 #include <xrpld/peerfinder/PeerfinderManager.h>
 
@@ -46,5 +45,3 @@ public:
 
 }  // namespace PeerFinder
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/peerfinder/detail/SourceStrings.h b/src/xrpld/peerfinder/detail/SourceStrings.h
index 2babe1d616..1cf6d81040 100644
--- a/src/xrpld/peerfinder/detail/SourceStrings.h
+++ b/src/xrpld/peerfinder/detail/SourceStrings.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PEERFINDER_SOURCESTRINGS_H_INCLUDED
-#define XRPL_PEERFINDER_SOURCESTRINGS_H_INCLUDED
+#pragma once
 
 #include <xrpld/peerfinder/detail/Source.h>
 
@@ -22,5 +21,3 @@ public:
 
 }  // namespace PeerFinder
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/peerfinder/detail/Store.h b/src/xrpld/peerfinder/detail/Store.h
index d3b283eabf..dab50b3ce0 100644
--- a/src/xrpld/peerfinder/detail/Store.h
+++ b/src/xrpld/peerfinder/detail/Store.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PEERFINDER_STORE_H_INCLUDED
-#define XRPL_PEERFINDER_STORE_H_INCLUDED
+#pragma once
 
 namespace xrpl {
 namespace PeerFinder {
@@ -31,5 +30,3 @@ public:
 
 }  // namespace PeerFinder
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/peerfinder/detail/StoreSqdb.h b/src/xrpld/peerfinder/detail/StoreSqdb.h
index 63ba03e913..f5461d489a 100644
--- a/src/xrpld/peerfinder/detail/StoreSqdb.h
+++ b/src/xrpld/peerfinder/detail/StoreSqdb.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PEERFINDER_STORESQDB_H_INCLUDED
-#define XRPL_PEERFINDER_STORESQDB_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/rdb/PeerFinder.h>
 #include <xrpld/core/SociDB.h>
@@ -86,5 +85,3 @@ private:
 
 }  // namespace PeerFinder
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/peerfinder/detail/Tuning.h b/src/xrpld/peerfinder/detail/Tuning.h
index ff93e5ee76..910d251dff 100644
--- a/src/xrpld/peerfinder/detail/Tuning.h
+++ b/src/xrpld/peerfinder/detail/Tuning.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PEERFINDER_TUNING_H_INCLUDED
-#define XRPL_PEERFINDER_TUNING_H_INCLUDED
+#pragma once
 
 #include <array>
 
@@ -115,5 +114,3 @@ std::chrono::seconds constexpr recentAttemptDuration(60);
 
 }  // namespace PeerFinder
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/peerfinder/detail/iosformat.h b/src/xrpld/peerfinder/detail/iosformat.h
index 0a0b18fba0..d05db42d23 100644
--- a/src/xrpld/peerfinder/detail/iosformat.h
+++ b/src/xrpld/peerfinder/detail/iosformat.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PEERFINDER_IOSFORMAT_H_INCLUDED
-#define XRPL_PEERFINDER_IOSFORMAT_H_INCLUDED
+#pragma once
 
 #include <ostream>
 #include <sstream>
@@ -174,5 +173,3 @@ rField(T const& t, int width = 8, int pad = 0)
 /** @} */
 
 }  // namespace beast
-
-#endif
diff --git a/src/xrpld/peerfinder/make_Manager.h b/src/xrpld/peerfinder/make_Manager.h
index a86e6d4ccb..846907e08c 100644
--- a/src/xrpld/peerfinder/make_Manager.h
+++ b/src/xrpld/peerfinder/make_Manager.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_PEERFINDER_MAKE_MANAGER_H_INCLUDED
-#define XRPL_PEERFINDER_MAKE_MANAGER_H_INCLUDED
+#pragma once
 
 #include <xrpld/peerfinder/PeerfinderManager.h>
 
@@ -21,5 +20,3 @@ make_Manager(
 
 }  // namespace PeerFinder
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/perflog/detail/PerfLogImp.h b/src/xrpld/perflog/detail/PerfLogImp.h
index 598f711cda..6e58aeb16e 100644
--- a/src/xrpld/perflog/detail/PerfLogImp.h
+++ b/src/xrpld/perflog/detail/PerfLogImp.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_BASICS_PERFLOGIMP_H
-#define XRPL_BASICS_PERFLOGIMP_H
+#pragma once
 
 #include <xrpld/rpc/detail/Handler.h>
 
@@ -175,5 +174,3 @@ public:
 
 }  // namespace perf
 }  // namespace xrpl
-
-#endif  // XRPL_BASICS_PERFLOGIMP_H
diff --git a/src/xrpld/rpc/BookChanges.h b/src/xrpld/rpc/BookChanges.h
index 68ad094dc9..a2ea9cabf7 100644
--- a/src/xrpld/rpc/BookChanges.h
+++ b/src/xrpld/rpc/BookChanges.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_BOOKCHANGES_H_INCLUDED
-#define XRPL_RPC_BOOKCHANGES_H_INCLUDED
+#pragma once
 
 #include <xrpl/json/json_value.h>
 #include <xrpl/protocol/LedgerFormats.h>
@@ -193,5 +192,3 @@ computeBookChanges(std::shared_ptr<L const> const& lpAccepted)
 
 }  // namespace RPC
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/CTID.h b/src/xrpld/rpc/CTID.h
index aad8c0f5c1..ba96236a7f 100644
--- a/src/xrpld/rpc/CTID.h
+++ b/src/xrpld/rpc/CTID.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_CTID_H_INCLUDED
-#define XRPL_RPC_CTID_H_INCLUDED
+#pragma once
 
 #include <boost/regex.hpp>
 
@@ -111,5 +110,3 @@ decodeCTID(T const ctid) noexcept
 
 }  // namespace RPC
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/Context.h b/src/xrpld/rpc/Context.h
index 8bb0bd3cbc..7ff02a9e8b 100644
--- a/src/xrpld/rpc/Context.h
+++ b/src/xrpld/rpc/Context.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_CONTEXT_H_INCLUDED
-#define XRPL_RPC_CONTEXT_H_INCLUDED
+#pragma once
 
 #include <xrpld/rpc/InfoSub.h>
 #include <xrpld/rpc/Role.h>
@@ -54,5 +53,3 @@ struct GRPCContext : public Context
 
 }  // namespace RPC
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/DeliveredAmount.h b/src/xrpld/rpc/DeliveredAmount.h
index f201d4b6cc..54e3476683 100644
--- a/src/xrpld/rpc/DeliveredAmount.h
+++ b/src/xrpld/rpc/DeliveredAmount.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_DELIVEREDAMOUNT_H_INCLUDED
-#define XRPL_RPC_DELIVEREDAMOUNT_H_INCLUDED
+#pragma once
 
 #include <xrpl/protocol/Protocol.h>
 #include <xrpl/protocol/STAmount.h>
@@ -55,5 +54,3 @@ getDeliveredAmount(
 
 }  // namespace RPC
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/GRPCHandlers.h b/src/xrpld/rpc/GRPCHandlers.h
index 603d26c055..ac419c18ee 100644
--- a/src/xrpld/rpc/GRPCHandlers.h
+++ b/src/xrpld/rpc/GRPCHandlers.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_GRPCHANDLER_H_INCLUDED
-#define XRPL_RPC_GRPCHANDLER_H_INCLUDED
+#pragma once
 
 #include <xrpld/rpc/Context.h>
 
@@ -30,5 +29,3 @@ std::pair<org::xrpl::rpc::v1::GetLedgerDiffResponse, grpc::Status>
 doLedgerDiffGrpc(RPC::GRPCContext<org::xrpl::rpc::v1::GetLedgerDiffRequest>& context);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/InfoSub.h b/src/xrpld/rpc/InfoSub.h
index 2816a1637c..7d4d4f06c8 100644
--- a/src/xrpld/rpc/InfoSub.h
+++ b/src/xrpld/rpc/InfoSub.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NET_INFOSUB_H_INCLUDED
-#define XRPL_NET_INFOSUB_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/misc/Manifest.h>
 
@@ -223,5 +222,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/MPTokenIssuanceID.h b/src/xrpld/rpc/MPTokenIssuanceID.h
index 1cd1e173f4..2b2eef3b38 100644
--- a/src/xrpld/rpc/MPTokenIssuanceID.h
+++ b/src/xrpld/rpc/MPTokenIssuanceID.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_MPTOKENISSUANCEID_H_INCLUDED
-#define XRPL_RPC_MPTOKENISSUANCEID_H_INCLUDED
+#pragma once
 
 #include <xrpl/basics/base_uint.h>
 #include <xrpl/json/json_forwards.h>
@@ -36,5 +35,3 @@ insertMPTokenIssuanceID(
 
 }  // namespace RPC
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/Output.h b/src/xrpld/rpc/Output.h
index 431cbb6bbf..1c74562842 100644
--- a/src/xrpld/rpc/Output.h
+++ b/src/xrpld/rpc/Output.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_OUTPUT_H_INCLUDED
-#define XRPL_RPC_OUTPUT_H_INCLUDED
+#pragma once
 
 #include <boost/utility/string_ref.hpp>
 
@@ -16,5 +15,3 @@ stringOutput(std::string& s)
 
 }  // namespace RPC
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/RPCCall.h b/src/xrpld/rpc/RPCCall.h
index e54816a749..30f50f8f72 100644
--- a/src/xrpld/rpc/RPCCall.h
+++ b/src/xrpld/rpc/RPCCall.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NET_RPCCALL_H_INCLUDED
-#define XRPL_NET_RPCCALL_H_INCLUDED
+#pragma once
 
 #include <xrpld/core/Config.h>
 
@@ -59,5 +58,3 @@ rpcClient(
     std::unordered_map<std::string, std::string> const& headers = {});
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/RPCHandler.h b/src/xrpld/rpc/RPCHandler.h
index 0b91528605..519740b75d 100644
--- a/src/xrpld/rpc/RPCHandler.h
+++ b/src/xrpld/rpc/RPCHandler.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_RPCHANDLER_H_INCLUDED
-#define XRPL_RPC_RPCHANDLER_H_INCLUDED
+#pragma once
 
 #include <xrpld/rpc/Context.h>
 #include <xrpld/rpc/Status.h>
@@ -18,5 +17,3 @@ roleRequired(unsigned int version, bool betaEnabled, std::string const& method);
 
 }  // namespace RPC
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/RPCSub.h b/src/xrpld/rpc/RPCSub.h
index b6bb32aaf3..53c46139cb 100644
--- a/src/xrpld/rpc/RPCSub.h
+++ b/src/xrpld/rpc/RPCSub.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_NET_RPCSUB_H_INCLUDED
-#define XRPL_NET_RPCSUB_H_INCLUDED
+#pragma once
 
 #include <xrpld/rpc/InfoSub.h>
 
@@ -34,5 +33,3 @@ make_RPCSub(
     Logs& logs);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/Request.h b/src/xrpld/rpc/Request.h
index 80e83802b5..233f45185b 100644
--- a/src/xrpld/rpc/Request.h
+++ b/src/xrpld/rpc/Request.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_REQUEST_H_INCLUDED
-#define XRPL_RPC_REQUEST_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/Journal.h>
 #include <xrpl/json/json_value.h>
@@ -44,5 +43,3 @@ private:
 
 }  // namespace RPC
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/Role.h b/src/xrpld/rpc/Role.h
index 04b288600a..554f9c1765 100644
--- a/src/xrpld/rpc/Role.h
+++ b/src/xrpld/rpc/Role.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SERVER_ROLE_H_INCLUDED
-#define XRPL_SERVER_ROLE_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/net/IPEndpoint.h>
 #include <xrpl/json/json_value.h>
@@ -71,5 +70,3 @@ std::string_view
 forwardedFor(http_request_type const& request);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/ServerHandler.h b/src/xrpld/rpc/ServerHandler.h
index 59ef9444c1..0810b303e9 100644
--- a/src/xrpld/rpc/ServerHandler.h
+++ b/src/xrpld/rpc/ServerHandler.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_SERVERHANDLER_H_INCLUDED
-#define XRPL_RPC_SERVERHANDLER_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/main/Application.h>
 #include <xrpld/app/main/CollectorManager.h>
@@ -200,5 +199,3 @@ make_ServerHandler(
     CollectorManager& cm);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/Status.h b/src/xrpld/rpc/Status.h
index 8ff969181d..34d621a3bb 100644
--- a/src/xrpld/rpc/Status.h
+++ b/src/xrpld/rpc/Status.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_STATUS_H_INCLUDED
-#define XRPL_RPC_STATUS_H_INCLUDED
+#pragma once
 
 #include <xrpl/beast/utility/instrumentation.h>
 #include <xrpl/protocol/ErrorCodes.h>
@@ -130,5 +129,3 @@ private:
 
 }  // namespace RPC
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/detail/Handler.h b/src/xrpld/rpc/detail/Handler.h
index 504b447774..f6fadd9cbd 100644
--- a/src/xrpld/rpc/detail/Handler.h
+++ b/src/xrpld/rpc/detail/Handler.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_HANDLER_H_INCLUDED
-#define XRPL_RPC_HANDLER_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/LedgerMaster.h>
 #include <xrpld/app/misc/NetworkOPs.h>
@@ -112,5 +111,3 @@ conditionMet(Condition condition_required, T& context)
 
 }  // namespace RPC
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/detail/LegacyPathFind.h b/src/xrpld/rpc/detail/LegacyPathFind.h
index d175e7c532..139075b53d 100644
--- a/src/xrpld/rpc/detail/LegacyPathFind.h
+++ b/src/xrpld/rpc/detail/LegacyPathFind.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_LEGACYPATHFIND_H_INCLUDED
-#define XRPL_RPC_LEGACYPATHFIND_H_INCLUDED
+#pragma once
 
 #include <atomic>
 
@@ -29,5 +28,3 @@ private:
 
 }  // namespace RPC
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/detail/RPCHelpers.h b/src/xrpld/rpc/detail/RPCHelpers.h
index 65cec14925..1b5e06ce42 100644
--- a/src/xrpld/rpc/detail/RPCHelpers.h
+++ b/src/xrpld/rpc/detail/RPCHelpers.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_RPCHELPERS_H_INCLUDED
-#define XRPL_RPC_RPCHELPERS_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/misc/NetworkOPs.h>
 #include <xrpld/app/misc/TxQ.h>
@@ -152,5 +151,3 @@ keypairForSignature(Json::Value const& params, Json::Value& error, unsigned int
 }  // namespace RPC
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/detail/RPCLedgerHelpers.h b/src/xrpld/rpc/detail/RPCLedgerHelpers.h
index 37ec66b584..6ea6e3cb78 100644
--- a/src/xrpld/rpc/detail/RPCLedgerHelpers.h
+++ b/src/xrpld/rpc/detail/RPCLedgerHelpers.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_RPCLEDGERHELPERS_H_INCLUDED
-#define XRPL_RPC_RPCLEDGERHELPERS_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/misc/NetworkOPs.h>
 #include <xrpld/app/misc/TxQ.h>
@@ -171,5 +170,3 @@ getOrAcquireLedger(RPC::JsonContext const& context);
 }  // namespace RPC
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/detail/TransactionSign.h b/src/xrpld/rpc/detail/TransactionSign.h
index 2e3c21651e..cc85d67815 100644
--- a/src/xrpld/rpc/detail/TransactionSign.h
+++ b/src/xrpld/rpc/detail/TransactionSign.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_TRANSACTIONSIGN_H_INCLUDED
-#define XRPL_RPC_TRANSACTIONSIGN_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/misc/LoadFeeTrack.h>
 #include <xrpld/app/misc/NetworkOPs.h>
@@ -121,5 +120,3 @@ transactionSubmitMultiSigned(
 
 }  // namespace RPC
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/detail/Tuning.h b/src/xrpld/rpc/detail/Tuning.h
index c0b939a4fe..e9dd2c37d7 100644
--- a/src/xrpld/rpc/detail/Tuning.h
+++ b/src/xrpld/rpc/detail/Tuning.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_TUNING_H_INCLUDED
-#define XRPL_RPC_TUNING_H_INCLUDED
+#pragma once
 
 namespace xrpl {
 namespace RPC {
@@ -72,5 +71,3 @@ static int constexpr max_auto_src_cur = 88;
 
 }  // namespace RPC
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/detail/WSInfoSub.h b/src/xrpld/rpc/detail/WSInfoSub.h
index fd791cbce7..8ed5ff8d6d 100644
--- a/src/xrpld/rpc/detail/WSInfoSub.h
+++ b/src/xrpld/rpc/detail/WSInfoSub.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_WSINFOSUB_H
-#define XRPL_RPC_WSINFOSUB_H
+#pragma once
 
 #include <xrpld/rpc/InfoSub.h>
 #include <xrpld/rpc/Role.h>
@@ -63,5 +62,3 @@ public:
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/handlers/GetCounts.h b/src/xrpld/rpc/handlers/GetCounts.h
index de2c4f2f96..60c7a3b693 100644
--- a/src/xrpld/rpc/handlers/GetCounts.h
+++ b/src/xrpld/rpc/handlers/GetCounts.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_HANDLERS_GETCOUNTS_H_INCLUDED
-#define XRPL_RPC_HANDLERS_GETCOUNTS_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/main/Application.h>
 
@@ -9,5 +8,3 @@ Json::Value
 getCountsJson(Application& app, int minObjectCount);
 
 }
-
-#endif
diff --git a/src/xrpld/rpc/handlers/Handlers.h b/src/xrpld/rpc/handlers/Handlers.h
index 773186237b..a5a96baa31 100644
--- a/src/xrpld/rpc/handlers/Handlers.h
+++ b/src/xrpld/rpc/handlers/Handlers.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_HANDLERS_HANDLERS_H_INCLUDED
-#define XRPL_RPC_HANDLERS_HANDLERS_H_INCLUDED
+#pragma once
 
 #include <xrpld/rpc/handlers/LedgerHandler.h>
 
@@ -150,5 +149,3 @@ doValidatorInfo(RPC::JsonContext&);
 Json::Value
 doVaultInfo(RPC::JsonContext&);
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/handlers/LedgerHandler.h b/src/xrpld/rpc/handlers/LedgerHandler.h
index 3285118d11..418958e9f1 100644
--- a/src/xrpld/rpc/handlers/LedgerHandler.h
+++ b/src/xrpld/rpc/handlers/LedgerHandler.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_HANDLERS_LEDGER_H_INCLUDED
-#define XRPL_RPC_HANDLERS_LEDGER_H_INCLUDED
+#pragma once
 
 #include <xrpld/app/ledger/LedgerMaster.h>
 #include <xrpld/app/ledger/LedgerToJson.h>
@@ -59,5 +58,3 @@ private:
 
 }  // namespace RPC
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/handlers/Version.h b/src/xrpld/rpc/handlers/Version.h
index b1383511ed..ed80bf3729 100644
--- a/src/xrpld/rpc/handlers/Version.h
+++ b/src/xrpld/rpc/handlers/Version.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_XRPL_RPC_HANDLERS_VERSION_H
-#define XRPL_XRPL_RPC_HANDLERS_VERSION_H
+#pragma once
 
 #include <xrpl/protocol/ApiVersion.h>
 
@@ -42,5 +41,3 @@ private:
 
 }  // namespace RPC
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/handlers/WalletPropose.h b/src/xrpld/rpc/handlers/WalletPropose.h
index 42c7973055..4eb72c7e46 100644
--- a/src/xrpld/rpc/handlers/WalletPropose.h
+++ b/src/xrpld/rpc/handlers/WalletPropose.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_XRPL_RPC_HANDLERS_WALLETPROPOSE_H
-#define XRPL_XRPL_RPC_HANDLERS_WALLETPROPOSE_H
+#pragma once
 
 #include <xrpl/json/json_value.h>
 
@@ -9,5 +8,3 @@ Json::Value
 walletPropose(Json::Value const& params);
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/rpc/json_body.h b/src/xrpld/rpc/json_body.h
index cadae1c024..6f8025d876 100644
--- a/src/xrpld/rpc/json_body.h
+++ b/src/xrpld/rpc/json_body.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_RPC_JSON_BODY_H
-#define XRPL_RPC_JSON_BODY_H
+#pragma once
 
 #include <xrpl/json/json_value.h>
 #include <xrpl/json/to_string.h>
@@ -85,5 +84,3 @@ struct json_body
 };
 
 }  // namespace xrpl
-
-#endif
diff --git a/src/xrpld/shamap/NodeFamily.h b/src/xrpld/shamap/NodeFamily.h
index 14c2ebb093..ab555919ac 100644
--- a/src/xrpld/shamap/NodeFamily.h
+++ b/src/xrpld/shamap/NodeFamily.h
@@ -1,5 +1,4 @@
-#ifndef XRPL_SHAMAP_NODEFAMILY_H_INCLUDED
-#define XRPL_SHAMAP_NODEFAMILY_H_INCLUDED
+#pragma once
 
 #include <xrpl/shamap/Family.h>
 
@@ -84,5 +83,3 @@ private:
 };
 
 }  // namespace xrpl
-
-#endif