diff --git a/net/updatedd/files/S55ddns b/net/updatedd/files/S55ddns
index b02d57917..75df45190 100644
--- a/net/updatedd/files/S55ddns
+++ b/net/updatedd/files/S55ddns
@@ -1,3 +1,6 @@
+#!/bin/sh
+. /etc/nvram.sh
+
 ddnsupdate=$(nvram get ddns_update)
 [ "$ddnsupdate" = 1 ]&& {
 	service=$(nvram get ddns_service)