diff --git a/bin/domainname/domainname.c b/bin/domainname/domainname.c
index fe6d2bf94c99..80137fa91712 100644
--- a/bin/domainname/domainname.c
+++ b/bin/domainname/domainname.c
@@ -63,6 +63,8 @@ main(int argc, char *argv[])
 
 	while ((ch = getopt(argc, argv, "")) != -1)
 		switch (ch) {
+		case '?':
+			/* fall through */
 		default:
 			usage();
 		}