diff --git a/restapi/index.php b/restapi/index.php
index f9fcecbce..982b9f98a 100644
--- a/restapi/index.php
+++ b/restapi/index.php
@@ -2268,19 +2268,19 @@ class RestapiController { /* {{{ */
     } /* }}} */
 
     function addUserAccessToFolder($request, $response, $args) { /* {{{ */
-        return changeFolderAccess($request, $response, $args, 'add', 'user');
+        return $this->changeFolderAccess($request, $response, $args, 'add', 'user');
     } /* }}} */
 
     function addGroupAccessToFolder($request, $response, $args) { /* {{{ */
-        return changeFolderAccess($request, $response, $args, 'add', 'group');
+        return $this->changeFolderAccess($request, $response, $args, 'add', 'group');
     } /* }}} */
 
     function removeUserAccessFromFolder($request, $response, $args) { /* {{{ */
-        return changeFolderAccess($request, $response, $args, 'remove', 'user');
+        return $this->changeFolderAccess($request, $response, $args, 'remove', 'user');
     } /* }}} */
 
     function removeGroupAccessFromFolder($request, $response, $args) { /* {{{ */
-        return changeFolderAccess($request, $response, $args, 'remove', 'group');
+        return $this->changeFolderAccess($request, $response, $args, 'remove', 'group');
     } /* }}} */
 
     function changeFolderAccess($request, $response, $args, $operationType, $userOrGroup) { /* {{{ */