diff --git a/data/web/user.php b/data/web/user.php
index 80b579c0..786ac11e 100644
--- a/data/web/user.php
+++ b/data/web/user.php
@@ -76,7 +76,7 @@ elseif (isset($_SESSION['mailcow_cc_role']) && $_SESSION['mailcow_cc_role'] == '
   $username = $_SESSION['mailcow_cc_username'];
   $mailboxdata = mailbox('get', 'mailbox_details', $username);
 
-  $clientconfigstr = "host=" . urlencode($mailcow_hostname) . "&email=" . urlencode($username) . "&name=" . urlencode($mailboxdata['name']) . "&port=" . urlencode($autodiscover_config['caldav']['port']);
+  $clientconfigstr = "host=" . urlencode($mailcow_hostname) . "&email=" . urlencode($username) . "&name=" . urlencode($mailboxdata['name']) . "&ui=" . urlencode($_SERVER['HTTP_HOST']) . "&port=" . urlencode($autodiscover_config['caldav']['port']);
   if ($autodiscover_config['useEASforOutlook'] == 'yes')
   $clientconfigstr .= "&outlookEAS=1";
   if (file_exists('thunderbird-plugins/version.csv')) {