diff --git a/core/modules/system/src/Tests/Update/UpdatePathTestBase.php b/core/modules/system/src/Tests/Update/UpdatePathTestBase.php
index 7102830..a8c91a9 100644
--- a/core/modules/system/src/Tests/Update/UpdatePathTestBase.php
+++ b/core/modules/system/src/Tests/Update/UpdatePathTestBase.php
@@ -130,9 +130,6 @@
   function __construct($test_id = NULL) {
     parent::__construct($test_id);
     $this->zlibInstalled = function_exists('gzopen');
-
-    // Set the update url.
-    $this->updateUrl = Url::fromRoute('system.db_update');
   }
 
   /**
@@ -156,6 +153,11 @@ protected function setUp() {
       return;
     }
 
+    // Set the update url. This must be set here rather than in
+    // self::__construct() or the old URL generator will leak additional test
+    // sites.
+    $this->updateUrl = Url::fromRoute('system.db_update');
+
     // These methods are called from parent::setUp().
     $this->setBatch();
     $this->initUserSession();
@@ -241,14 +243,15 @@ protected function runUpdates() {
       'required' => TRUE,
     ]]]);
 
-    // Avoid outbound language negotiation during updates.
-    // @see https://www.drupal.org/node/2555183
-    $this->drupalGet($this->updateUrl, ['language' => 'en', 'alias' => TRUE]);
+    $this->drupalGet($this->updateUrl);
     $this->clickLink(t('Continue'));
 
     // Run the update hooks.
     $this->clickLink(t('Apply pending updates'));
 
+    // Ensure there are no failed updates.
+    $this->assertNoRaw('<strong>' . t('Failed:') . '</strong>');
+
     // The config schema can be incorrect while the update functions are being
     // executed. But once the update has been completed, it needs to be valid
     // again. Assert the schema of all configuration objects now.