diff --git a/core/vendor/filemanager/UploadHandler.php b/core/vendor/filemanager/UploadHandler.php
index a005ba8c..2f685593 100644
--- a/core/vendor/filemanager/UploadHandler.php
+++ b/core/vendor/filemanager/UploadHandler.php
@@ -1614,7 +1614,7 @@ class UploadHandler
         return $this->generate_response($response, $print_response);
     }
 
-    protected function basename($filepath, $suffix = null) {
+    protected function basename($filepath, $suffix = "") {
         $splited = preg_split('/\//', rtrim ($filepath, '/ '));
         return substr(basename('X'.$splited[count($splited)-1], $suffix), 1);
     }