--- a/debianutils/mktemp.c
+++ b/debianutils/mktemp.c
@@ -50,7 +50,7 @@ int mktemp_main(int argc UNUSED_PARAM, c
 	opts = getopt32(argv, "dqtp:", &path);
 
 	chp = argv[optind] ? argv[optind] : xstrdup("tmp.XXXXXX");
-	if (chp[0] != '/' || (opts & 8))
+	if (!strchr(chp, '/') || (opts & 8))
 		chp = concat_path_file(path, chp);
 
 	if (opts & 1) { /* -d */