diff --git a/phpBB/includes/functions_user.php b/phpBB/includes/functions_user.php
index 31b886a7de..a87b79d3a6 100644
--- a/phpBB/includes/functions_user.php
+++ b/phpBB/includes/functions_user.php
@@ -2765,10 +2765,11 @@ function group_user_add($group_id, $user_id_ary = false, $username_ary = false,
 	 * @event core.group_add_user_before
 	 * @var	int		group_id		ID of the group to which users are added
 	 * @var	string 	group_name		Name of the group
-	 * @var	array	user_id_ary		IDs of the users which are added
-	 * @var	array	username_ary	names of the users which are added
+	 * @var	array	user_id_ary		IDs of the users to be added
+	 * @var	array	username_ary	Names of the users to be added
 	 * @var	int		pending			Pending setting, 1 if user(s) added are pending
-	 * @since 3.3.14
+	 * @var	array	add_id_ary		IDs of the users to be added who are not members yet
+	 * @since 3.3.15-RC1
 	 */
 	$vars = array(
 		'group_id',
@@ -2776,6 +2777,7 @@ function group_user_add($group_id, $user_id_ary = false, $username_ary = false,
 		'user_id_ary',
 		'username_ary',
 		'pending',
+		'add_id_ary',
 	);
 	extract($phpbb_dispatcher->trigger_event('core.group_add_user_before', compact($vars)));