diff --git a/etc/rc.dyndns.update b/etc/rc.dyndns.update
index ca81432490..9a31ca12a9 100755
--- a/etc/rc.dyndns.update
+++ b/etc/rc.dyndns.update
@@ -30,7 +30,7 @@
 */
 
 require_once("config.inc");
-require_once("functions");
+require_once("functions.inc");
 require_once("filter.inc");
 
 log_error("Informational: services_dyndns_configure() is starting.");