diff --git a/3rd/msgpack/include/mpack1.h b/3rd/msgpack/include/mpack1.h
index 225cb021..2446a1f1 100644
--- a/3rd/msgpack/include/mpack1.h
+++ b/3rd/msgpack/include/mpack1.h
@@ -5,7 +5,7 @@
 
 typedef bool (*is_mpack_ext_t)(py_Type type);
 typedef bool (*py_to_mpack_ext_t)(py_Ref object, mpack_writer_t* writer);
-typedef bool (*mpack_to_py_ext_t)(mpack_node_t node);
+typedef bool (*mpack_to_py_ext_t)(py_StackRef tmp, mpack_node_t node);
 
 void mpack_config_exttype_callbacks(is_mpack_ext_t is_ext,
                                     py_to_mpack_ext_t to_mpack,