diff -u b/core/modules/shortcut/lib/Drupal/shortcut/Tests/ShortcutLinksTest.php b/core/modules/shortcut/lib/Drupal/shortcut/Tests/ShortcutLinksTest.php
--- b/core/modules/shortcut/lib/Drupal/shortcut/Tests/ShortcutLinksTest.php
+++ b/core/modules/shortcut/lib/Drupal/shortcut/Tests/ShortcutLinksTest.php
@@ -7,6 +7,8 @@
 
 namespace Drupal\shortcut\Tests;
 
+use Drupal\Component\Utility\String;
+
 /**
  * Defines shortcut links test cases.
  */