diff --git a/src/core/init/responder.php b/src/core/init/responder.php
index 6abce79..80614bf 100644
--- a/src/core/init/responder.php
+++ b/src/core/init/responder.php
@@ -94,7 +94,7 @@ class Responder {
     $response->content_type = "ms-json";
     $response->content = new MSAutodiscoverJSONResponse();
     $response->content->Protocol = "AutodiscoverV1";
-    $response->content->Url = "https://" . $_SERVER['HTTP_HOST'] . "/Autodiscover/Autodiscover.xml";
+    $response->content->Url = Core::$Config["BaseURL"] . "/Autodiscover/Autodiscover.xml";
     return $response;
   }
   private function dummy_response(){
diff --git a/src/sample-config/config.sample.ini b/src/sample-config/config.sample.ini
index a163648..e6ddf1d 100644
--- a/src/sample-config/config.sample.ini
+++ b/src/sample-config/config.sample.ini
@@ -6,6 +6,8 @@ Domain = example.com
 LogonDomain = example.local
 RequireAuthDomain = false
 
+BaseURL = "https://autoconfig.example.com"
+
 ; Admin User configuration
 ; not in use yet
 ;[AdminUser]