diff --git a/core/modules/rest/src/Tests/RegisterUserTest.php b/core/modules/rest/src/Tests/RegisterUserTest.php
index 3f654bf..09ccdf2 100644
--- a/core/modules/rest/src/Tests/RegisterUserTest.php
+++ b/core/modules/rest/src/Tests/RegisterUserTest.php
@@ -97,7 +97,7 @@ protected function testRegisterUser() {
     // Obtain the uid from the header.
     $url_parts = explode('/', $this->drupalGetHeader('location'));
     $id = end($url_parts);
-    $this->assertHeader('Location', 'http://drupal8/user/' . $id);
+    $this->assertHeader('Location', $GLOBALS['base_url'] . '/user/' . $id);
 
     $this->assertTrue((bool) \Drupal::entityQuery('user')
       ->condition('name', 'Druplicon')