diff --git a/phpBB/includes/notifications/type/post_in_queue.php b/phpBB/includes/notifications/type/post_in_queue.php
index ca02b8d85a..5f8f9988c5 100644
--- a/phpBB/includes/notifications/type/post_in_queue.php
+++ b/phpBB/includes/notifications/type/post_in_queue.php
@@ -93,7 +93,7 @@ class phpbb_notifications_type_post_in_queue extends phpbb_notifications_type_po
 		$sql = 'SELECT *
 			FROM ' . USER_NOTIFICATIONS_TABLE . "
 			WHERE item_type = '" . self::$notification_option['id'] . "'
-				AND " . $db->sql_in_set('user_id', $auth_approve[$topic['forum_id']]['m_approve']);
+				AND " . $db->sql_in_set('user_id', $auth_approve[$post['forum_id']]['m_approve']);
 		$result = $db->sql_query($sql);
 		while ($row = $db->sql_fetchrow($result))
 		{