diff --git a/gobject/ChangeLog b/gobject/ChangeLog
index 1695fb67a..657d86ca1 100644
--- a/gobject/ChangeLog
+++ b/gobject/ChangeLog
@@ -1,3 +1,9 @@
+2007-09-20  Carlos Garnacho  <carlos@imendio.com>
+
+	* gtypemodule.h: make sure we define GType g_define_type_id in
+	G_G_DEFINE_DYNAMIC_TYPE_EXTENDED so it works together with
+	G_IMPLEMENT_INTERFACE. (#478459)
+
 2007-09-19  Matthias Clasen  <mclasen@redhat.com>
 
 	* === Released 2.14.1 ===
diff --git a/gobject/gtypemodule.h b/gobject/gtypemodule.h
index a99238976..46858f59d 100644
--- a/gobject/gtypemodule.h
+++ b/gobject/gtypemodule.h
@@ -86,6 +86,7 @@ type_name##_get_type (void) \
 static void \
 type_name##_register_type (GTypeModule *type_module) \
 { \
+  GType g_define_type_id; \
   const GTypeInfo g_define_type_info = { \
     sizeof (TypeName##Class), \
     (GBaseInitFunc) NULL, \
@@ -103,6 +104,7 @@ type_name##_register_type (GTypeModule *type_module) \
 						     #TypeName, \
 						     &g_define_type_info, \
 						     (GTypeFlags) flags); \
+  g_define_type_id = type_name##_type_id; \
   { CODE ; } \
 }