diff --git a/lib/api/folder_list.php b/lib/api/folder_list.php
index 4607fb8..3b448a0 100644
--- a/lib/api/folder_list.php
+++ b/lib/api/folder_list.php
@@ -1,151 +1,154 @@
 <?php
 /*
  +--------------------------------------------------------------------------+
  | This file is part of the Kolab File API                                  |
  |                                                                          |
  | Copyright (C) 2012-2014, Kolab Systems AG                                |
  |                                                                          |
  | This program is free software: you can redistribute it and/or modify     |
  | it under the terms of the GNU Affero General Public License as published |
  | by the Free Software Foundation, either version 3 of the License, or     |
  | (at your option) any later version.                                      |
  |                                                                          |
  | This program is distributed in the hope that it will be useful,          |
  | but WITHOUT ANY WARRANTY; without even the implied warranty of           |
  | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the             |
  | GNU Affero General Public License for more details.                      |
  |                                                                          |
  | You should have received a copy of the GNU Affero General Public License |
  | along with this program. If not, see <http://www.gnu.org/licenses/>      |
  +--------------------------------------------------------------------------+
  | Author: Aleksander Machniak <machniak@kolabsys.com>                      |
  +--------------------------------------------------------------------------+
 */
 
 class file_api_folder_list extends file_api_common
 {
     /**
      * Request handler
      */
     public function handle()
     {
         parent::handle();
 
         $params   = $this->folder_list_params();
         $search   = isset($params['search']) ? mb_strtoupper($params['search']) : null;
         $drivers  = $this->api->get_drivers(true, $admin_drivers);
         $errors   = array();
         $has_more = false;
 
         if (isset($this->args['folder']) && strlen($this->args['folder'])) {
             list($driver, $path) = $this->api->get_driver($this->args['folder']);
 
             $title          = $driver->title();
             $params['path'] = $path;
 
             try {
                 $folders = $this->folder_list($driver, $params, true);
             }
             catch (Exception $e) {
                 $folders = array();
                 if ($e->getCode() == file_storage::ERROR_NOAUTH) {
                     if (!in_array($title, $admin_drivers)) {
                         // inform UI about to ask user for credentials
                         $errors[$title] = $this->parse_metadata($driver->driver_metadata());
                     }
                     else {
                         $errors[$title] = array('error' => file_storage::ERROR_NOAUTH);
                     }
                 }
             }
 
             $drivers = array();
         }
         else {
-            // get folders from default driver
             $backend = $this->api->get_backend();
-            $folders = $this->folder_list($backend, $params);
+
+            // get folders from default driver
+            if (!$this->rc->config->get('fileapi_backend_storage_disabled')) {
+                $folders = $this->folder_list($backend, $params);
+            }
         }
 
         // old result format
         if ($this->api->client_version() < 2) {
             return $folders;
         }
 
         // get folders from external sources
         foreach ($drivers as $driver) {
             $title  = $driver->title();
             $prefix = $title . file_storage::SEPARATOR;
 
             // folder exists in main source, replace it with external one
             foreach ($folders as $idx => $folder) {
                 if (is_array($folder)) {
                     $folder = $folder['folder'];
                 }
                 if ($folder == $title || strpos($folder, $prefix) === 0) {
                     unset($folders[$idx]);
                 }
             }
 
             if ($search === null || strpos(mb_strtoupper($title), $search) !== false) {
                 if ($folder = $this->driver_root_folder($driver, $params)) {
                     $has_more  = $has_more || count($folders) > 0;
                     $folders[] = $folder;
                 }
             }
 
             if ($driver != $backend && $params['level'] != 1) {
                 try {
                     $_folders = $this->folder_list($driver, $params);
                     if (!empty($_folders)) {
                         $folders  = array_merge($folders, $_folders);
                         $has_more = true;
                         unset($_folders);
                     }
                 }
                 catch (Exception $e) {
                     if ($e->getCode() == file_storage::ERROR_NOAUTH) {
                         if (!in_array($title, $admin_drivers)) {
                             // inform UI about to ask user for credentials
                             $errors[$title] = $this->parse_metadata($driver->driver_metadata());
                         }
                         else {
                             $errors[$title] = array('error' => file_storage::ERROR_NOAUTH);
                         }
                     }
                 }
             }
         }
 
         // re-sort the list
         if ($has_more) {
             usort($folders, array('file_utils', 'sort_folder_comparator'));
         }
 
         return array(
             'list'        => array_values($folders),
             'auth_errors' => $errors,
         );
     }
 
     protected function driver_root_folder($driver, $params)
     {
         $title  = $driver->title();
         $folder = $params['extended'] ? array('folder' => $title) : $title;
 
         if ($params['permissions'] || ($params['type'] & file_storage::FILTER_WRITABLE)) {
             if ($readonly = !($driver->folder_rights('') & file_storage::ACL_WRITE)) {
                 if ($params['permissions']) {
                     $folder['readonly'] = true;
                 }
             }
         }
         else {
             $readonly = false;
         }
 
         if (!$readonly || !($params['type'] & file_storage::FILTER_WRITABLE)) {
             return $folder;
         }
     }
 }