diff --git a/src/vim.h b/src/vim.h
index 887a76d..cb2a9e5 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -1326,6 +1326,7 @@
     EVENT_SHELLFILTERPOST,	/* after ":1,2!cmd", ":w !cmd", ":r !cmd". */
     EVENT_TEXTCHANGED,		/* text was modified */
     EVENT_TEXTCHANGEDI,		/* text was modified in Insert mode*/
+    EVENT_CMDUNDEFINED,		/* command undefined */
     NUM_EVENTS			/* MUST be the last one */
 };