--- gtk2-3.4.3/ext/gtk2/rbgtk.c.orig	2022-11-08 15:25:33.507083460 +0900
+++ gtk2-3.4.3/ext/gtk2/rbgtk.c	2022-11-08 15:25:46.160087108 +0900
@@ -539,6 +539,7 @@ rg_m_show_uri(G_GNUC_UNUSED VALUE self,
 void 
 Init_gtk_gtk(void)
 {
+    id_relative_callbacks = rb_intern("relative_callback");
     id_call = rb_intern("call");
     id__windows__ = rb_intern("__windows__");
     id__quit_callbacks__ = rb_intern("__quit_callbacks__");