diff --git a/src/ripple/app/consensus/RCLValidations.cpp b/src/ripple/app/consensus/RCLValidations.cpp
index c44f98bd48..6311677c21 100644
--- a/src/ripple/app/consensus/RCLValidations.cpp
+++ b/src/ripple/app/consensus/RCLValidations.cpp
@@ -182,13 +182,6 @@ handleNewValidation(
           << " [" << val->getSerializer().slice() << "]";
     };
 
-    if (!val->isFieldPresent(sfLedgerSequence))
-    {
-        if (j.error())
-            dmp(j.error(), "missing ledger sequence field");
-        return false;
-    }
-
     // masterKey is seated only if validator is trusted or listed
     if (masterKey)
     {
diff --git a/src/ripple/overlay/impl/PeerImp.cpp b/src/ripple/overlay/impl/PeerImp.cpp
index 6b5446fb34..4518d61557 100644
--- a/src/ripple/overlay/impl/PeerImp.cpp
+++ b/src/ripple/overlay/impl/PeerImp.cpp
@@ -2170,7 +2170,8 @@ PeerImp::onMessage(std::shared_ptr<protocol::TMValidation> const& m)
     }
     catch (std::exception const& e)
     {
-        JLOG(p_journal_.warn()) << "Validation: Exception, " << e.what();
+        JLOG(p_journal_.warn())
+            << "Exception processing validation: " << e.what();
         fee_ = Resource::feeInvalidRequest;
     }
 }
diff --git a/src/ripple/protocol/STValidation.h b/src/ripple/protocol/STValidation.h
index 8410860007..996b56887d 100644
--- a/src/ripple/protocol/STValidation.h
+++ b/src/ripple/protocol/STValidation.h
@@ -122,6 +122,11 @@ public:
         // Perform additional initialization
         f(*this);
 
+        // This is a logic error because we should never assemble a
+        // validation without a ledger sequence number.
+        if (!isFieldPresent(sfLedgerSequence))
+            LogicError("Missing ledger sequence in validation");
+
         // Finally, sign the validation and mark it as trusted:
         setFlag(vfFullyCanonicalSig);
         setFieldVL(sfSignature, signDigest(pk, sk, getSigningHash()));
diff --git a/src/ripple/protocol/impl/STValidation.cpp b/src/ripple/protocol/impl/STValidation.cpp
index 458b601bf7..779a031a7e 100644
--- a/src/ripple/protocol/impl/STValidation.cpp
+++ b/src/ripple/protocol/impl/STValidation.cpp
@@ -34,7 +34,7 @@ STValidation::validationFormat()
     static SOTemplate const format{
         {sfFlags, soeREQUIRED},
         {sfLedgerHash, soeREQUIRED},
-        {sfLedgerSequence, soeOPTIONAL},
+        {sfLedgerSequence, soeREQUIRED},
         {sfCloseTime, soeOPTIONAL},
         {sfLoadFee, soeOPTIONAL},
         {sfAmendments, soeOPTIONAL},
diff --git a/src/test/app/RCLValidations_test.cpp b/src/test/app/RCLValidations_test.cpp
index a84b44c301..6b4f16d42c 100644
--- a/src/test/app/RCLValidations_test.cpp
+++ b/src/test/app/RCLValidations_test.cpp
@@ -20,6 +20,8 @@
 #include <ripple/app/consensus/RCLValidations.h>
 #include <ripple/app/ledger/Ledger.h>
 #include <ripple/basics/Log.h>
+#include <ripple/basics/StringUtilities.h>
+#include <ripple/basics/base_uint.h>
 #include <ripple/beast/unit_test.h>
 #include <ripple/ledger/View.h>
 #include <test/jtx.h>
@@ -310,6 +312,89 @@ class RCLValidations_test : public beast::unit_test::suite
         BEAST_EXPECT(trie.branchSupport(ledg_259) == 4);
     }
 
+    void
+    testLedgerSequence()
+    {
+        testcase("Validations with and without the LedgerSequence field");
+
+        auto const nodeID =
+            from_hex_text<NodeID>("38ECC15DBD999DE4CE70A6DC69A4166AB18031A7");
+
+        try
+        {
+            std::string const withLedgerSequence =
+                "228000000126034B9FFF2926460DC55185937F7F41DD7977F21B9DF95FCB61"
+                "9E5132ABB0D7ADEA0F7CE8A9347871A34250179D85BDE824F57FFE0AC8F89B"
+                "55FCB89277272A1D83D08ADEC98096A88EF723137321029D19FB0940E5C0D8"
+                "5873FA711999944A687D129DA5C33E928C2751FC1B31EB3276463044022022"
+                "6229CF66A678EE021F62CA229BA006B41939845004D3FAF8347C6FFBB7C613"
+                "02200BE9CD3629FD67C6C672BD433A2769FCDB36B1ECA2292919C58A86224E"
+                "2BF5970313C13F00C1FC4A53E60AB02C864641002B3172F38677E29C26C540"
+                "6685179B37E1EDAC157D2D480E006395B76F948E3E07A45A05FE10230D88A7"
+                "993C71F97AE4B1F2D11F4AFA8FA1BC8827AD4C0F682C03A8B671DCDF6B5C4D"
+                "E36D44243A684103EF8825BA44241B3BD880770BFA4DA21C71805768318553"
+                "68CBEC6A3154FDE4A7676E3012E8230864E95A58C60FD61430D7E1B4D33531"
+                "95F2981DC12B0C7C0950FFAC30CD365592B8EE40489BA01AE2F7555CAC9C98"
+                "3145871DC82A42A31CF5BAE7D986E83A7D2ECE3AD5FA87AB2195AE015C9504"
+                "69ABF0B72EAACED318F74886AE9089308AF3B8B10B7192C4E613E1D2E4D9BA"
+                "64B2EE2D5232402AE82A6A7220D953";
+
+            if (auto ret = strUnHex(withLedgerSequence); ret)
+            {
+                SerialIter sit(makeSlice(*ret));
+
+                auto val = std::make_shared<STValidation>(
+                    std::ref(sit),
+                    [nodeID](PublicKey const& pk) { return nodeID; },
+                    false);
+
+                BEAST_EXPECT(val);
+                BEAST_EXPECT(calcNodeID(val->getSignerPublic()) == nodeID);
+                BEAST_EXPECT(val->isFieldPresent(sfLedgerSequence));
+            }
+        }
+        catch (std::exception const& ex)
+        {
+            fail(std::string("Unexpected exception thrown: ") + ex.what());
+        }
+
+        try
+        {
+            std::string const withoutLedgerSequence =
+                "22800000012926460DC55185937F7F41DD7977F21B9DF95FCB619E5132ABB0"
+                "D7ADEA0F7CE8A9347871A34250179D85BDE824F57FFE0AC8F89B55FCB89277"
+                "272A1D83D08ADEC98096A88EF723137321029D19FB0940E5C0D85873FA7119"
+                "99944A687D129DA5C33E928C2751FC1B31EB3276473045022100BE2EA49CF2"
+                "FFB7FE7A03F6860B8C35FEA04A064C7023FE28EC97E5A32E85DEC4022003B8"
+                "5D1D497F504B34F089D5BDB91BD888690C3D3A242A0FEF1DD52875FBA02E03"
+                "13C13F00C1FC4A53E60AB02C864641002B3172F38677E29C26C5406685179B"
+                "37E1EDAC157D2D480E006395B76F948E3E07A45A05FE10230D88A7993C71F9"
+                "7AE4B1F2D11F4AFA8FA1BC8827AD4C0F682C03A8B671DCDF6B5C4DE36D4424"
+                "3A684103EF8825BA44241B3BD880770BFA4DA21C7180576831855368CBEC6A"
+                "3154FDE4A7676E3012E8230864E95A58C60FD61430D7E1B4D3353195F2981D"
+                "C12B0C7C0950FFAC30CD365592B8EE40489BA01AE2F7555CAC9C983145871D"
+                "C82A42A31CF5BAE7D986E83A7D2ECE3AD5FA87AB2195AE015C950469ABF0B7"
+                "2EAACED318F74886AE9089308AF3B8B10B7192C4E613E1D2E4D9BA64B2EE2D"
+                "5232402AE82A6A7220D953";
+
+            if (auto ret = strUnHex(withoutLedgerSequence); ret)
+            {
+                SerialIter sit(makeSlice(*ret));
+
+                auto val = std::make_shared<STValidation>(
+                    std::ref(sit),
+                    [nodeID](PublicKey const& pk) { return nodeID; },
+                    false);
+
+                fail("Expected exception not thrown from validation");
+            }
+        }
+        catch (std::exception const& ex)
+        {
+            pass();
+        }
+    }
+
 public:
     void
     run() override
@@ -317,6 +402,7 @@ public:
         testChangeTrusted();
         testRCLValidatedLedger();
         testLedgerTrieRCLValidatedLedger();
+        testLedgerSequence();
     }
 };