diff --git a/SeedDMS_Core/Core/inc.ClassFolder.php b/SeedDMS_Core/Core/inc.ClassFolder.php
index 0431aef47..51e78ab1a 100644
--- a/SeedDMS_Core/Core/inc.ClassFolder.php
+++ b/SeedDMS_Core/Core/inc.ClassFolder.php
@@ -1375,6 +1375,9 @@ class SeedDMS_Core_Folder extends SeedDMS_Core_Object {
 	function addAccess($mode, $userOrGroupID, $isUser) { /* {{{ */
 		$db = $this->_dms->getDB();
 
+        if($mode < M_NONE || $mode > M_ALL)
+            return false;
+
 		$userOrGroup = ($isUser) ? "`userID`" : "`groupID`";
 
 		$queryStr = "INSERT INTO `tblACLs` (`target`, `targetType`, ".$userOrGroup.", `mode`) VALUES