diff --git a/Lib/lua/luarun.swg b/Lib/lua/luarun.swg
index f39a7009d..a6959a65f 100644
--- a/Lib/lua/luarun.swg
+++ b/Lib/lua/luarun.swg
@@ -1049,7 +1049,7 @@ SWIGINTERN int  SWIG_Lua_class_tostring(lua_State *L)
   lua_getfield(L, -1, ".type");
   className = lua_tostring(L, -1);
 
-  lua_pushfstring(L, "<%s userdata: %p>", className, userData->ptr);
+  lua_pushfstring(L, "<%s userdata: %p::%p>", className, userdata, userData->ptr);
   return 1;
 }