diff --git a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
index fab2ba5e4f88f..e2da9aa7b7c1c 100644
--- a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp
@@ -3903,7 +3903,7 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> {
            ReturnType->getPrimitiveSizeInBits());
 
     if (I.arg_size() == 3) {
-      auto *AccumulatorType = cast<FixedVectorType>(I.getOperand(0)->getType());
+      [[maybe_unused]] auto *AccumulatorType = cast<FixedVectorType>(I.getOperand(0)->getType());
       assert(AccumulatorType == ReturnType);
     }