diff --git a/authentication.php b/authentication.php
index ccafadc..97a4d41 100644
--- a/authentication.php
+++ b/authentication.php
@@ -128,6 +128,7 @@ class authentication
       $alreadyAuth = $pre->email;
     if ($this->appName !== null)
       $auth->appName = $this->appName;
+    @header ('X-Frame-Options: SAMEORIGIN');
     echo $auth->pageHTML ($this->route->baseURL(), $message, $url,
                           $alreadyAuth);
   }