diff --git a/thunarx/thunarx.h b/thunarx/thunarx.h
index 2ec42526..06d0d8f5 100644
--- a/thunarx/thunarx.h
+++ b/thunarx/thunarx.h
@@ -83,11 +83,17 @@ type_name##_register_type (ThunarxProviderPlugin *thunarx_define_type_plugin) \
   type_name##_type = thunarx_define_type_id; \
 }
 
+#define COMMA() ,
+#define EMPTY()
+#define DEFER(id) id EMPTY()
+
 #define THUNARX_IMPLEMENT_INTERFACE(TYPE_IFACE, iface_init) \
 { \
   static const GInterfaceInfo thunarx_implement_interface_info = \
   { \
-    (GInterfaceInitFunc) (void (*)(void)) iface_init \
+    (GInterfaceInitFunc) (void (*)(void)) iface_init DEFER(COMMA)() \
+    NULL DEFER(COMMA)() \
+    NULL \
   }; \
   thunarx_provider_plugin_add_interface (thunarx_define_type_plugin, thunarx_define_type_id, TYPE_IFACE, &thunarx_implement_interface_info); \
 }