diff --git a/include/wx/defs.h b/include/wx/defs.h
index 4b7e2f1df9..22a59d3d5b 100644
--- a/include/wx/defs.h
+++ b/include/wx/defs.h
@@ -1928,6 +1928,7 @@ typedef GtkWidget *WXWidget;
 
 #ifndef __WXGTK20__
 #define GTK_OBJECT_GET_CLASS(object) (GTK_OBJECT(object)->klass)
+#define GTK_CLASS_TYPE(klass) ((klass)->type)
 #endif
 
 #ifdef __WXGTK20__