diff --git a/calendar.php b/calendar.php
index 2ceef7a..5debec6 100644
--- a/calendar.php
+++ b/calendar.php
@@ -184,33 +184,6 @@ class calendar extends rcube_plugin
                     // @TODO: do EXPUNGE on kolab objects?
                 }
             }
-            // loading preinstalled sources
-            $preinstalled_sources = $this->rc->config->get('calendar_preinstalled_sources', FALSE);
-            if ($preinstalled_sources && is_array($preinstalled_sources)) {
-                $username = $this->rc->get_user_name();
-                $password = $this->rc->get_user_password();
-
-                foreach ($preinstalled_sources as $cal){
-                    $url  = $cal['caldav_url'];
-                    $user = $cal['caldav_user'];
-                    $pass = $cal['caldav_pass'];
-
-                    $url  = str_replace('%u', $username, $url);
-                    $user = str_replace('%u', $username, $user);
-                    $pass = str_replace('%p', $password, $pass);
-
-                    $cal['caldav_url']  = $url;
-                    $cal['caldav_user'] = $user;
-                    $cal['caldav_pass'] = $pass;
-
-                    $cal['new-source'] = true;
-
-                    if (!$this->driver->create_calendar($cal)) {
-                        $error_msg = 'Unable to add default calendars' . ($this->driver && $thi->driver->last_error ? ': ' . $this->driver->last_error :'');
-                        $this->rc->output->show_message($error_msg, 'error');
-                    }
-                }
-            }
         }
         else if ($args['task'] == 'settings') {
             // add hooks for Calendar settings
diff --git a/drivers/caldav/caldav_driver.php b/drivers/caldav/caldav_driver.php
index d17c2e7..4dc5a2e 100644
--- a/drivers/caldav/caldav_driver.php
+++ b/drivers/caldav/caldav_driver.php
@@ -101,9 +101,41 @@ class caldav_driver extends calendar_driver
         if(self::$debug === null)
             self::$debug = $this->rc->config->get('calendar_caldav_debug', False);
 
+        $this->_setup_preinstalled_sources();
         $this->_read_calendars();
     }
 
+    /**
+     * Setup preinstalled sources defined in config file
+     */
+    protected function _setup_preinstalled_sources()
+    {
+        $preinstalled_sources = $this->rc->config->get('calendar_preinstalled_sources', FALSE);
+        if ($preinstalled_sources && is_array($preinstalled_sources)) {
+            $username = $this->rc->get_user_name();
+            $password = $this->rc->get_user_password();
+
+            foreach ($preinstalled_sources as $cal){
+                $url  = $cal['caldav_url'];
+                $user = $cal['caldav_user'];
+                $pass = $cal['caldav_pass'];
+
+                $url  = str_replace('%u', $username, $url);
+                $user = str_replace('%u', $username, $user);
+                $pass = str_replace('%p', $password, $pass);
+
+                $cal['caldav_url']  = $url;
+                $cal['caldav_user'] = $user;
+                $cal['caldav_pass'] = $pass;
+
+                if (!$this->create_source($cal)) {
+                    $error_msg = 'Unable to add default calendars' . ($this->last_error ? ': ' . $this->last_error :'');
+                    $this->rc->output->show_message($error_msg, 'error');
+                }
+            }
+        }
+    }
+
     /**
      * Read available calendars for the current user and store them internally
      */
@@ -302,6 +334,7 @@ class caldav_driver extends calendar_driver
     {
         $source['caldav_url'] = self::_encode_url($source['caldav_url']);
 
+        // Skip already exiting sources
         $result = $this->rc->db->query("SELECT user_id, caldav_url, caldav_user FROM " . $this->db_sources . " WHERE user_id=? AND caldav_url=? AND caldav_user=?", $this->rc->user->ID, $source['caldav_url'], $source['caldav_user']);
         if($this->rc->db->affected_rows($result)) return true;