diff --git a/src/heap_utils.cc b/src/heap_utils.cc
index a1ca118e6c1f93..e71a65e600631e 100644
--- a/src/heap_utils.cc
+++ b/src/heap_utils.cc
@@ -42,7 +42,7 @@ class JSGraphJSNode : public EmbedderGraph::Node {
 
   struct Hash {
     inline size_t operator()(JSGraphJSNode* n) const {
-      return n->IdentityHash();
+      return static_cast<size_t>(n->IdentityHash());
     }
   };