diff --git a/inc/HTTPAuthSession.php b/inc/HTTPAuthSession.php
index 69795eaf..b80f012b 100644
--- a/inc/HTTPAuthSession.php
+++ b/inc/HTTPAuthSession.php
@@ -106,6 +106,8 @@ class HTTPAuthSession {
 
     header('HTTP/1.1 401 Unauthorized', true, 401 );
     header('Content-type: text/plain; ; charset="utf-8"' );
+    if ( $c->test_mode ) header( "Request-ID: " . request_id() );
+
     header( $auth_header );
     echo 'Please log in for access to this system.';
     if ( isset($_SERVER['PHP_AUTH_USER']) ) {