diff --git a/core/relinker/codegen/src/x86/X64InstructionDecoder.cpp b/core/relinker/codegen/src/x86/X64InstructionDecoder.cpp
index 0e5ebec82..7a0b2a001 100644
--- a/core/relinker/codegen/src/x86/X64InstructionDecoder.cpp
+++ b/core/relinker/codegen/src/x86/X64InstructionDecoder.cpp
@@ -481,6 +481,12 @@ DecodedInstructionInfo X64InstructionDecoder::DecodeInstruction(
             info.FlowKind = ControlFlowKind::Trap;
             return info;
         }
+        if (op == TwoByteUd1) {
+            if (pos < info.Length)
+                readModRm(pos, false);
+            info.FlowKind = ControlFlowKind::Trap;
+            return info;
+        }
         if (op >= TwoByteJccRel32Min && op <= TwoByteJccRel32Max) {
             std::int32_t disp = 0;
             std::memcpy(&disp, data + pos, 4);
diff --git a/core/relinker/codegen/tests/Amd64OnlyConverterTests.cpp b/core/relinker/codegen/tests/Amd64OnlyConverterTests.cpp
index f94034c19..87ed32b77 100644
--- a/core/relinker/codegen/tests/Amd64OnlyConverterTests.cpp
+++ b/core/relinker/codegen/tests/Amd64OnlyConverterTests.cpp
@@ -168,6 +168,9 @@ void decoderRipRelative() {
     }
     for (const auto& instruction : kRegisterVectorOperations)
         require(!decoder.DecodeInstruction(instruction.data(), instruction.size()).HasRipRelativeDisp, "Vector instruction without a RIP-relative operand was reported as RIP-relative");
+    const Bytes ud1 = {0x0F, 0xB9, 0x05, 0x10, 0x00, 0x00, 0x00};
+    const auto trap = decoder.DecodeInstruction(ud1.data(), ud1.size());
+    require(trap.Length == ud1.size() && trap.FlowKind == Codegen::ControlFlowKind::Trap && trap.HasRipRelativeDisp && read<std::int32_t>(ud1, trap.RipRelativeDispOffset) == 0x10, "UD1 was not decoded as a trap with its RIP-relative operand");
 }
 
 void decoderTwoByteOpcodeLengths() {
diff --git a/core/relinker/relinker/tests/StrictNidFilterTests.cpp b/core/relinker/relinker/tests/StrictNidFilterTests.cpp
index 63fbdac61..77d77d3f7 100644
--- a/core/relinker/relinker/tests/StrictNidFilterTests.cpp
+++ b/core/relinker/relinker/tests/StrictNidFilterTests.cpp
@@ -68,6 +68,17 @@ void deadTailAndExplicitEntry() {
     require(live.ImportSlots == std::set<std::uint64_t>{0x2000}, "Explicit entry after UD2 lost its import");
 }
 
+void ud1DeadTail() {
+    auto input = fixture();
+    emit(input, 0, {0x0F, 0xB9, 0xC0});
+    importThunk(input, 16, 0x2000);
+    require(AnalyzeStrictReachability(input).ImportSlots.empty(), "UD1 fallthrough retained a dead import");
+    input = fixture();
+    ripOperand(input, 0, {0x0F, 0xB9, 0x05}, 0x3000);
+    importThunk(input, 16, 0x2000);
+    require(AnalyzeStrictReachability(input).ImportSlots.empty(), "UD1 with a RIP-relative operand retained a dead import");
+}
+
 void conditionalTailCall() {
     auto input = fixture();
     emit(input, 0, {0x75, 0x0E, 0xC3});
@@ -283,6 +294,7 @@ void filterAndPltCompaction() {
 int main() {
     try {
         deadTailAndExplicitEntry();
+        ud1DeadTail();
         conditionalTailCall();
         callbackAndRelocationRoots();
         registerImportCall();