diff --git a/calendar/drivers/caldav/caldav_driver.php b/calendar/drivers/caldav/caldav_driver.php
index b39aeff..064de3d 100644
--- a/calendar/drivers/caldav/caldav_driver.php
+++ b/calendar/drivers/caldav/caldav_driver.php
@@ -270,7 +270,7 @@ public function edit_calendar($cal)
         );
 
         // Change password if specified
-        if (isset($cal["caldav_pass"])) {
+        if (isset($cal["caldav_pass"]) && !empty($cal["caldav_pass"])) {
             $query = $this->rc->db->query("UPDATE " . $this->db_calendars . "
             SET   caldav_pass=?
             WHERE calendar_id=?