diff -u b/core/modules/comment/src/Tests/CommentFieldsTest.php b/core/modules/comment/src/Tests/CommentFieldsTest.php
--- b/core/modules/comment/src/Tests/CommentFieldsTest.php
+++ b/core/modules/comment/src/Tests/CommentFieldsTest.php
@@ -8,6 +8,7 @@
 namespace Drupal\comment\Tests;
 
 use Drupal\comment\Plugin\Field\FieldType\CommentItemInterface;
+use Drupal\Core\Url;
 use Drupal\field\Entity\FieldStorageConfig;
 use Drupal\field\Entity\FieldConfig;
 use Drupal\comment\Entity\CommentType;
@@ -115,7 +116,8 @@
     $links = \Drupal::service('comment.link_builder')->buildCommentedEntityLinks($node, $context);
     $link_info = $links['comment__comment2']['#attached']['drupalSettings']['comment']['newCommentsLinks']['node']['comment2']['2'];
     $this->assertIdentical($link_info['new_comment_count'], 1);
-    $this->assertIdentical($link_info['first_new_comment_link'], '/node/2#new');
+    $url = Url::fromUri('internal:/node/2', ['fragment' => 'new'])->toString();
+    $this->assertIdentical($link_info['first_new_comment_link'], $url);
   }
 
   /**