diff --git a/mfbt/RefPtr.h b/mfbt/RefPtr.h
index 71d186ab40..d4f12dda44 100644
--- a/mfbt/RefPtr.h
+++ b/mfbt/RefPtr.h
@@ -214,8 +214,7 @@ public:
   RefPtr<T>&
   operator=(RefPtr<T> && aRefPtr)
   {
-    assign_assuming_AddRef(aRefPtr.mRawPtr);
-    aRefPtr.mRawPtr = nullptr;
+    assign_assuming_AddRef(aRefPtr.forget().take());
     return *this;
   }