diff --git a/include/flatbuffers/flatbuffers.h b/include/flatbuffers/flatbuffers.h
index 0fa31250f..ef4a693cc 100644
--- a/include/flatbuffers/flatbuffers.h
+++ b/include/flatbuffers/flatbuffers.h
@@ -333,7 +333,7 @@ public:
 
   // Change elements if you have a non-const pointer to this object.
   // Scalars only. See reflection.h, and the documentation.
-  void Mutate(uoffset_t i, T val) {
+  void Mutate(uoffset_t i, const T& val) {
     assert(i < size());
     WriteScalar(data() + i, val);
   }