diff -u b/core/includes/common.inc b/core/includes/common.inc
--- b/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -20,7 +20,6 @@
 use Drupal\Component\Utility\String;
 use Drupal\Component\Utility\Tags;
 use Drupal\Component\Utility\UrlHelper;
-use Drupal\Component\Utility\Xss;
 use Drupal\Core\Cache\Cache;
 use Drupal\Core\Language\LanguageInterface;
 use Drupal\Core\Render\RenderStackFrame;
diff -u b/core/lib/Drupal/Component/Utility/SafeMarkup.php b/core/lib/Drupal/Component/Utility/SafeMarkup.php
--- b/core/lib/Drupal/Component/Utility/SafeMarkup.php
+++ b/core/lib/Drupal/Component/Utility/SafeMarkup.php
@@ -7,6 +7,8 @@
 
 namespace Drupal\Component\Utility;
 
+use Drupal\Component\Utility\Xss;
+
 /**
  * Manages known safe strings for rendering at the theme layer.
  *
diff -u b/core/lib/Drupal/Core/Form/FormBuilder.php b/core/lib/Drupal/Core/Form/FormBuilder.php
--- b/core/lib/Drupal/Core/Form/FormBuilder.php
+++ b/core/lib/Drupal/Core/Form/FormBuilder.php
@@ -13,7 +13,6 @@
 use Drupal\Component\Utility\SafeMarkup;
 use Drupal\Component\Utility\String;
 use Drupal\Component\Utility\UrlHelper;
-use Drupal\Component\Utility\Xss;
 use Drupal\Core\Access\CsrfTokenGenerator;
 use Drupal\Core\DependencyInjection\ClassResolverInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;