diff --git a/src/Controller/SimplesamlphpAuthController.php b/src/Controller/SimplesamlphpAuthController.php
index 8a084f26c..d0e04b6f3 100644
--- a/src/Controller/SimplesamlphpAuthController.php
+++ b/src/Controller/SimplesamlphpAuthController.php
@@ -150,6 +150,7 @@ public function authenticate() {
     if (($return_to = $request->query->get('ReturnTo')) ||
         ($return_to = $request->request->get('ReturnTo')) ||
         ($return_to = $request->server->get('HTTP_REFERER'))) {
+      $return_to = \Drupal::request()->getSchemeAndHttpHost() . $return_to;
       if ($this->pathValidator->isValid($return_to) && UrlHelper::externalIsLocal($return_to, $base_url)) {
         $redirect = $return_to;
       }