diff --git a/scripts/pi-hole/php/groups.php b/scripts/pi-hole/php/groups.php
index 7d2fdc5f..7cab27dc 100644
--- a/scripts/pi-hole/php/groups.php
+++ b/scripts/pi-hole/php/groups.php
@@ -649,7 +649,7 @@ if ($_POST['action'] == 'get_groups') {
         }
 
         foreach ($addresses as $address) {
-            if(preg_match("/[^a-zA-Z0-9:\/?&%=~._-]/", $address) !== 0) {
+            if(preg_match("/[^a-zA-Z0-9:\/?&%=~._()-]/", $address) !== 0) {
                 throw new Exception('Invalid adlist URL');
             }