diff --git a/lib/permissions/permissionutil.inc.php b/lib/permissions/permissionutil.inc.php
index 40aa491..3a206d2 100644
--- a/lib/permissions/permissionutil.inc.php
+++ b/lib/permissions/permissionutil.inc.php
@@ -647,6 +647,9 @@ class KTPermissionUtil {
      */
     function inheritPermissionObject(&$oDocumentOrFolder, $aOptions = null) {
         global $default;
+
+        $oDocumentOrFolder->cacheGlobal=array();
+
         $bEvenIfNotOwner = KTUtil::arrayGet($aOptions, 'evenifnotowner');
         if (empty($bEvenIfNotOwner) && !KTPermissionUtil::isPermissionOwner($oDocumentOrFolder)) {
             return PEAR::raiseError(_kt("Document or Folder doesn't own its permission object"));