diff --git a/src/regexp.c b/src/regexp.c
index 1bd1261..61fc14d 100644
--- a/src/regexp.c
+++ b/src/regexp.c
@@ -1824,7 +1824,7 @@
     char_u	*s;
     typval_T	*listarg = argv + argskip;
 
-    if (!fp->uf_varargs && fp->uf_args.ga_len <= argskip)
+    if (!has_varargs(fp) && fp->uf_args.ga_len <= argskip)
 	// called function doesn't take a submatches argument
 	return argskip;