diff --git a/include/xrpl/beast/unit_test/runner.h b/include/xrpl/beast/unit_test/runner.h
index 9cb1042070..f0aea84280 100644
--- a/include/xrpl/beast/unit_test/runner.h
+++ b/include/xrpl/beast/unit_test/runner.h
@@ -67,7 +67,7 @@ public:
     }
 
     /** Returns the reference fee, if any. */
-    std::optional<std::int64_t> const&
+    [[nodiscard]] std::optional<std::int64_t> const&
     referenceFee() const
     {
         return referenceFee_;
diff --git a/include/xrpl/beast/unit_test/suite.h b/include/xrpl/beast/unit_test/suite.h
index 4304a418d3..10a70b6db2 100644
--- a/include/xrpl/beast/unit_test/suite.h
+++ b/include/xrpl/beast/unit_test/suite.h
@@ -285,7 +285,7 @@ public:
     referenceFee() const
     {
         assert(runner_);
-        if (!runner_)
+        if (runner_ == nullptr)
             return {};
         return runner_->referenceFee();
     }
diff --git a/src/libxrpl/ledger/CanonicalTXSet.cpp b/src/libxrpl/ledger/CanonicalTXSet.cpp
index df4e88e346..12cec5e321 100644
--- a/src/libxrpl/ledger/CanonicalTXSet.cpp
+++ b/src/libxrpl/ledger/CanonicalTXSet.cpp
@@ -42,7 +42,8 @@ CanonicalTXSet::accountKey(AccountID const& account)
 void
 CanonicalTXSet::insert(std::shared_ptr<STTx const> txn)
 {
-    Key key(accountKey(txn->getAccountID(sfAccount)), txn->getSeqProxy(), txn->getTransactionID());
+    Key const key(
+        accountKey(txn->getAccountID(sfAccount)), txn->getSeqProxy(), txn->getTransactionID());
     map_.emplace(key, std::move(txn));
 }
 
diff --git a/src/test/app/LedgerMaster_test.cpp b/src/test/app/LedgerMaster_test.cpp
index b36b0762a0..50fec54a5f 100644
--- a/src/test/app/LedgerMaster_test.cpp
+++ b/src/test/app/LedgerMaster_test.cpp
@@ -13,6 +13,7 @@
 #include <xrpl/protocol/SField.h>
 #include <xrpl/protocol/STObject.h>
 #include <xrpl/protocol/STTx.h>
+#include <xrpl/protocol/XRPAmount.h>
 
 #include <cstdint>
 #include <memory>
diff --git a/src/test/basics/PerfLog_test.cpp b/src/test/basics/PerfLog_test.cpp
index ac97aaaae5..800b400832 100644
--- a/src/test/basics/PerfLog_test.cpp
+++ b/src/test/basics/PerfLog_test.cpp
@@ -28,6 +28,7 @@
 #include <iterator>
 #include <limits>
 #include <memory>
+#include <optional>
 #include <ostream>
 #include <random>
 #include <string>
diff --git a/src/test/core/ClosureCounter_test.cpp b/src/test/core/ClosureCounter_test.cpp
index ce1a6cee62..f26cbaeaf1 100644
--- a/src/test/core/ClosureCounter_test.cpp
+++ b/src/test/core/ClosureCounter_test.cpp
@@ -7,6 +7,7 @@
 
 #include <atomic>
 #include <optional>
+#include <string>
 #include <thread>
 #include <utility>
 
diff --git a/src/test/jtx/impl/Env.cpp b/src/test/jtx/impl/Env.cpp
index b75cceadeb..bdc0ca630e 100644
--- a/src/test/jtx/impl/Env.cpp
+++ b/src/test/jtx/impl/Env.cpp
@@ -47,6 +47,7 @@
 #include <xrpl/protocol/TER.h>
 #include <xrpl/protocol/TxFlags.h>
 #include <xrpl/protocol/UintTypes.h>
+#include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/protocol/jss.h>
 #include <xrpl/server/NetworkOPs.h>
 
diff --git a/src/test/rpc/AccountTx_test.cpp b/src/test/rpc/AccountTx_test.cpp
index 7ad6ab66ec..2f14b6fab6 100644
--- a/src/test/rpc/AccountTx_test.cpp
+++ b/src/test/rpc/AccountTx_test.cpp
@@ -34,6 +34,7 @@
 #include <xrpl/protocol/STAmount.h>
 #include <xrpl/protocol/TER.h>
 #include <xrpl/protocol/TxFlags.h>
+#include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/protocol/jss.h>
 
 #include <boost/container/flat_set.hpp>
diff --git a/src/test/rpc/DeliveredAmount_test.cpp b/src/test/rpc/DeliveredAmount_test.cpp
index 1c08b0f162..9134a6e765 100644
--- a/src/test/rpc/DeliveredAmount_test.cpp
+++ b/src/test/rpc/DeliveredAmount_test.cpp
@@ -3,7 +3,6 @@
 #include <test/jtx/WSClient.h>
 #include <test/jtx/amount.h>
 #include <test/jtx/balance.h>
-#include <test/jtx/envconfig.h>
 #include <test/jtx/mpt.h>
 #include <test/jtx/pay.h>
 #include <test/jtx/sendmax.h>
@@ -19,10 +18,10 @@
 #include <xrpl/protocol/SField.h>
 #include <xrpl/protocol/TER.h>
 #include <xrpl/protocol/TxFlags.h>
+#include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/protocol/jss.h>
 
 #include <chrono>
-#include <utility>
 
 namespace xrpl::test {
 
diff --git a/src/test/rpc/LedgerClosed_test.cpp b/src/test/rpc/LedgerClosed_test.cpp
index 55590a4e2a..a7c1223a9a 100644
--- a/src/test/rpc/LedgerClosed_test.cpp
+++ b/src/test/rpc/LedgerClosed_test.cpp
@@ -2,15 +2,12 @@
 #include <test/jtx/Account.h>
 #include <test/jtx/Env.h>
 #include <test/jtx/amount.h>
-#include <test/jtx/envconfig.h>
 
 #include <xrpl/beast/unit_test/suite.h>
 #include <xrpl/protocol/Feature.h>
 #include <xrpl/protocol/SField.h>
 #include <xrpl/protocol/jss.h>
 
-#include <utility>
-
 namespace xrpl {
 
 class LedgerClosed_test : public beast::unit_test::Suite
diff --git a/src/test/rpc/LedgerEntry_test.cpp b/src/test/rpc/LedgerEntry_test.cpp
index ccdcb23f9b..41e2b5bd90 100644
--- a/src/test/rpc/LedgerEntry_test.cpp
+++ b/src/test/rpc/LedgerEntry_test.cpp
@@ -46,6 +46,7 @@
 #include <xrpl/protocol/STVector256.h>
 #include <xrpl/protocol/STXChainBridge.h>
 #include <xrpl/protocol/TxFlags.h>
+#include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/protocol/jss.h>
 
 #include <algorithm>
diff --git a/src/test/rpc/LedgerRPC_test.cpp b/src/test/rpc/LedgerRPC_test.cpp
index 6e6b6228af..8f96b44328 100644
--- a/src/test/rpc/LedgerRPC_test.cpp
+++ b/src/test/rpc/LedgerRPC_test.cpp
@@ -20,6 +20,7 @@
 #include <xrpl/json/to_string.h>
 #include <xrpl/protocol/ErrorCodes.h>
 #include <xrpl/protocol/TER.h>
+#include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/protocol/jss.h>
 
 #include <memory>
diff --git a/src/test/rpc/LedgerRequest_test.cpp b/src/test/rpc/LedgerRequest_test.cpp
index 65af2832ca..badadefb81 100644
--- a/src/test/rpc/LedgerRequest_test.cpp
+++ b/src/test/rpc/LedgerRequest_test.cpp
@@ -5,16 +5,18 @@
 #include <test/jtx/amount.h>
 #include <test/jtx/envconfig.h>
 
+#include <xrpld/core/Config.h>
+
 #include <xrpl/beast/unit_test/suite.h>
 #include <xrpl/json/json_value.h>
 #include <xrpl/protocol/ApiVersion.h>
 #include <xrpl/protocol/ErrorCodes.h>
+#include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/protocol/jss.h>
 
 #include <functional>
 #include <memory>
 #include <string>
-#include <utility>
 
 namespace xrpl::RPC {
 
diff --git a/src/test/rpc/TransactionEntry_test.cpp b/src/test/rpc/TransactionEntry_test.cpp
index f33a8261a1..02fefaf3ef 100644
--- a/src/test/rpc/TransactionEntry_test.cpp
+++ b/src/test/rpc/TransactionEntry_test.cpp
@@ -1,12 +1,9 @@
 #include <test/jtx/Account.h>
 #include <test/jtx/Env.h>
 #include <test/jtx/amount.h>
-#include <test/jtx/envconfig.h>
 #include <test/jtx/offer.h>
 #include <test/jtx/pay.h>
 
-#include <xrpld/core/Config.h>
-
 #include <xrpl/basics/base_uint.h>
 #include <xrpl/basics/contract.h>
 #include <xrpl/beast/unit_test/suite.h>
@@ -15,6 +12,7 @@
 #include <xrpl/json/to_string.h>
 #include <xrpl/protocol/ApiVersion.h>
 #include <xrpl/protocol/ErrorCodes.h>
+#include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/protocol/jss.h>
 
 #include <functional>
diff --git a/src/test/rpc/Transaction_test.cpp b/src/test/rpc/Transaction_test.cpp
index 338fd2abe5..0e780bee36 100644
--- a/src/test/rpc/Transaction_test.cpp
+++ b/src/test/rpc/Transaction_test.cpp
@@ -24,6 +24,7 @@
 #include <xrpl/protocol/STObject.h>
 #include <xrpl/protocol/STTx.h>
 #include <xrpl/protocol/TER.h>
+#include <xrpl/protocol/XRPAmount.h>
 #include <xrpl/protocol/jss.h>
 #include <xrpl/protocol/serialize.h>
 
diff --git a/src/xrpld/app/main/Main.cpp b/src/xrpld/app/main/Main.cpp
index d208942343..a86c759e8a 100644
--- a/src/xrpld/app/main/Main.cpp
+++ b/src/xrpld/app/main/Main.cpp
@@ -36,6 +36,7 @@
 #include <exception>
 #include <iostream>
 #include <memory>
+#include <optional>
 #include <ostream>
 #include <string>
 #include <vector>
@@ -548,7 +549,7 @@ run(int argc, char** argv)
 
         if (vm.contains("unittest-arg"))
             argument = vm["unittest-arg"].as<std::string>();
-        if (vm.count("unittest-fee"))
+        if (vm.contains("unittest-fee") != 0u)
             referenceFee = vm["unittest-fee"].as<std::int64_t>();
 
         std::size_t numJobs = 1;
@@ -571,8 +572,9 @@ run(int argc, char** argv)
     }
     // LCOV_EXCL_START
 
-    if (vm.count("unittest-jobs") || vm.count("unittest-arg") || vm.count("unittest-fee") ||
-        vm.count("unittest-log") || vm.count("unittest-ipv6"))
+    if ((vm.contains("unittest-jobs") != 0u) || (vm.contains("unittest-arg") != 0u) ||
+        (vm.contains("unittest-fee") != 0u) || (vm.contains("unittest-log") != 0u) ||
+        (vm.contains("unittest-ipv6") != 0u))
     {
         // unittest jobs only makes sense with `unittest`
         std::cerr << "xrpld: unittest-related parameter specified without '--unittest'.\n";