diff --git a/core/modules/simpletest/src/WebTestBase.php b/core/modules/simpletest/src/WebTestBase.php
index c41364c..1be82b1 100644
--- a/core/modules/simpletest/src/WebTestBase.php
+++ b/core/modules/simpletest/src/WebTestBase.php
@@ -2955,7 +2955,7 @@ protected function buildUrl($path, array $options = array()) {
     // interactive installer tests.
     else if ($this->container->has('url_generator')) {
       if (UrlHelper::isExternal($path)) {
-        return Url::fromUri($path)->toString();
+        return Url::fromUri($path, $options)->toString();
       }
       else {
         $uri = $path === '<front>' ? 'base:' : 'base:' . $path;