diff --git a/mkfs.c b/mkfs.c
index 9073f872..7d635dc2 100644
--- a/mkfs.c
+++ b/mkfs.c
@@ -356,6 +356,7 @@ static u64 parse_profile(char *s)
 		return 0;
 	} else {
 		fprintf(stderr, "Unknown profile %s\n", s);
+		exit(1);
 	}
 	/* not reached */
 	return 0;