diff --git a/include/memory b/include/memory
index 4c3a18c9..7763c197 100644
--- a/include/memory
+++ b/include/memory
@@ -4076,6 +4076,7 @@ private:
             {
                 __e->__weak_this_.__ptr_ = const_cast<_Yp*>(static_cast<const _Yp*>(__e));
                 __e->__weak_this_.__cntrl_ = __cntrl_;
+                __cntrl_->__add_weak();
             }
         }