diff --git a/sql/item.h b/sql/item.h
index 9bcb913d5c5..3136bb00394 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -3287,6 +3287,12 @@ public:
     else
       Item_direct_ref::save_in_result_field(no_conversions);
   }
+
+  void cleanup()
+  {
+    null_ref_table= NULL;
+    Item_direct_ref::cleanup();
+  }
 };