--- a/third_party/binaryen/src/third_party/llvm-project/include/llvm/ADT/DenseMap.h
+++ b/third_party/binaryen/src/third_party/llvm-project/include/llvm/ADT/DenseMap.h
@@ -136,6 +136,7 @@ public:
         }
       }
       assert(NumEntries == 0 && "Node count imbalance!");
+      (void)NumEntries;
     }
     setNumEntries(0);
     setNumTombstones(0);