diff --git a/services/univention-apache/js/ucs/startsite.js b/services/univention-apache/js/ucs/startsite.js
index 659801a..5292875 100644
--- a/services/univention-apache/js/ucs/startsite.js
+++ b/services/univention-apache/js/ucs/startsite.js
@@ -232,6 +232,11 @@ define([
 					protocol = 'https:';
 					port = '';
 				}
+				if (!port && window.location.port) {
+					// in case of access to https://host:1443/
+					protocol = window.location.protocol;
+					port = window.location.port;
+				}
 				if (port) {
 					port = ':' + port;
 				}