diff --git a/includes/IPBAuth.php b/includes/IPBAuth.php
index 2c386e1..861f320 100644
--- a/includes/IPBAuth.php
+++ b/includes/IPBAuth.php
@@ -206,9 +206,10 @@ public static function updateUser(&$user)
                             if (is_array($groupmap)) {
                                 foreach ($groupmap as $ug_wiki => $ug_ipb) {
                                     $user_has_ug = in_array($ug_wiki, $user->getEffectiveGroups());
-                                    if (in_array($ug_ipb, $groups) && !$user_has_ug) {
+                                    $user_needs_ug = !empty(array_uintersect((array)$ug_ipb, $groups, 'version_compare'));
+                                    if ($user_needs_ug && !$user_has_ug) {
                                         $user->addGroup($ug_wiki);
-                                    } elseif (!in_array($ug_ipb, $groups) && $user_has_ug) {
+                                    } elseif (!$user_needs_ug && $user_has_ug) {
                                         $user->removeGroup($ug_wiki);
                                     }
                                 }