diff --git a/gtk2_ardour/luainstance.cc b/gtk2_ardour/luainstance.cc
index f8d0cba01c..ee7d2780a2 100644
--- a/gtk2_ardour/luainstance.cc
+++ b/gtk2_ardour/luainstance.cc
@@ -1169,6 +1169,7 @@ LuaInstance::register_classes (lua_State* L, bool sandbox)
 #undef IMPORTDISPOSITION
 #undef TEMPOEDITBEHAVIOR
 #undef NOTENAMEDISPLAY
+#undef REGIONEDITDISPOSITION
 
 #define ZOOMFOCUS(NAME) .addConst (stringify(NAME), (Editing::ZoomFocus)Editing::NAME)
 #define GRIDTYPE(NAME) .addConst (stringify(NAME), (Editing::GridType)Editing::NAME)