diff --git a/py/objtype.c b/py/objtype.c
index 25c2dee994d7..d40f619fae24 100644
--- a/py/objtype.c
+++ b/py/objtype.c
@@ -1292,8 +1292,7 @@ static mp_obj_t mp_obj_new_type(qstr name, mp_obj_t bases_tuple, mp_obj_t locals
         mp_raise_TypeError(MP_ERROR_TEXT("multiple bases have instance lay-out conflict"));
     }
 
-    mp_map_t *locals_map = &MP_OBJ_TYPE_GET_SLOT(o, locals_dict)->map;
-    mp_map_elem_t *elem = mp_map_lookup(locals_map, MP_OBJ_NEW_QSTR(MP_QSTR___new__), MP_MAP_LOOKUP);
+    mp_map_elem_t *elem = mp_map_lookup(&locals_ptr->map, MP_OBJ_NEW_QSTR(MP_QSTR___new__), MP_MAP_LOOKUP);
     if (elem != NULL) {
         // __new__ slot exists; check if it is a function
         if (mp_obj_is_fun(elem->value)) {