diff --git a/include/utils/RefBase.h b/include/utils/RefBase.h
index d92cfb0..0af7e6a 100644
--- a/include/utils/RefBase.h
+++ b/include/utils/RefBase.h
@@ -115,6 +115,7 @@
     // used to override the RefBase destruction.
     class Destroyer {
         friend class RefBase;
+        friend class weakref_type;
     public:
         virtual ~Destroyer();
     private: