diff --git a/include/tscore/MT_hashtable.h b/include/tscore/MT_hashtable.h
index cb6a80d34ee..92ada4d8863 100644
--- a/include/tscore/MT_hashtable.h
+++ b/include/tscore/MT_hashtable.h
@@ -354,10 +354,10 @@ template <class key_t, class data_t> class MTHashTable
     }
   }
 
-  ProxyMutex *
+  Ptr<ProxyMutex>
   lock_for_key(key_t key)
   {
-    return locks[part_num(key)].get();
+    return locks[part_num(key)];
   }
 
   int