diff --git a/interface/web/dns/form/dns_ns.tform.php b/interface/web/dns/form/dns_ns.tform.php
index 063a896de3719f8c9bd6da4543383dcfa5720f88..e20a7892bfce61b2ed904f7fcfe782c9ca7c41f9 100644
--- a/interface/web/dns/form/dns_ns.tform.php
+++ b/interface/web/dns/form/dns_ns.tform.php
@@ -86,7 +86,7 @@ $form["tabs"]['dns'] = array (
 					'type' => 'TOLOWER')
 			),
 			'validators' => array (  0 => array ( 'type' => 'REGEX',
-					'regex' => '/^[a-zA-Z0-9\.\-]{0,255}$/',
+					'regex' => '/^[_a-zA-Z0-9\.\-]{0,255}$/',
 					'errmsg'=> 'name_error_regex'),
 			),
 			'default' => '',