diff --git a/src/autocmd.c b/src/autocmd.c
index 1abd410..be8e72d 100644
--- a/src/autocmd.c
+++ b/src/autocmd.c
@@ -2329,7 +2329,7 @@
  * Returns allocated string, or NULL for end of autocommands.
  */
     char_u *
-getnextac(int c UNUSED, void *cookie, int indent UNUSED)
+getnextac(int c UNUSED, void *cookie, int indent UNUSED, int do_concat UNUSED)
 {
     AutoPatCmd	    *acp = (AutoPatCmd *)cookie;
     char_u	    *retval;