diff --git a/common/password.c b/common/password.c
index e5a333d..3c08ab7 100644
--- a/common/password.c
+++ b/common/password.c
@@ -161,6 +161,9 @@
 	unsigned char *buf = (unsigned char *)default_passwd;
 	unsigned char c;
 
+	if (ARRAY_SIZE(default_passwd) == 1)
+		return -ENOSYS;
+
 	if (!sum || length < 1)
 		return -EINVAL;