diff --git a/src/fileio.c b/src/fileio.c
index 4145c71..3af64c4 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -8785,9 +8785,11 @@
     else
     {
 	sfname = vim_strsave(fname);
-	/* Don't try expanding FileType, Syntax, WindowID or QuickFixCmd* */
+	/* Don't try expanding FileType, Syntax, FuncUndefined, WindowID or
+	 * QuickFixCmd* */
 	if (event == EVENT_FILETYPE
 		|| event == EVENT_SYNTAX
+		|| event == EVENT_FUNCUNDEFINED
 		|| event == EVENT_REMOTEREPLY
 		|| event == EVENT_SPELLFILEMISSING
 		|| event == EVENT_QUICKFIXCMDPRE