diff --git a/interface/web/dns/form/dns_cname.tform.php b/interface/web/dns/form/dns_cname.tform.php
index ca2419b1fd2211e918ecb49854d6254542766eaa..957e6e19e5256a470a4751b8c4c0e89a89d5d9c1 100644
--- a/interface/web/dns/form/dns_cname.tform.php
+++ b/interface/web/dns/form/dns_cname.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' => '',