diff --git a/js/src/vm/RegExpObject.h b/js/src/vm/RegExpObject.h
index 28adbb36fc..4f35908087 100644
--- a/js/src/vm/RegExpObject.h
+++ b/js/src/vm/RegExpObject.h
@@ -128,7 +128,7 @@ class RegExpShared : public gc::TenuredCell
     };
 
     /* Source to the RegExp, for lazy compilation. */
-    HeapPtr<JSAtom*>   source;
+    GCPtr<JSAtom*>     source;
 
     RegExpFlag         flags;
     bool               canStringMatch;