diff --git a/core/modules/system/src/Tests/Form/FormCacheTest.php b/core/modules/system/src/Tests/Form/FormCacheTest.php
index 2124404..dffdf6f 100644
--- a/core/modules/system/src/Tests/Form/FormCacheTest.php
+++ b/core/modules/system/src/Tests/Form/FormCacheTest.php
@@ -8,6 +8,7 @@
 namespace Drupal\system\Tests\Form;
 
 use Drupal\Core\Form\FormState;
+use Drupal\Core\Session\AnonymousUserSession;
 use Drupal\Core\Session\UserSession;
 use Drupal\simpletest\DrupalUnitTestBase;
 
@@ -88,7 +89,8 @@ function testCacheToken() {
    * Tests the form cache without a logged-in user.
    */
   function testNoCacheToken() {
-    $this->container->set('current_user', new UserSession(array('uid' => 0)));
+    $current_user = $this->container->get('current_user');
+    $current_user->setAccount(new AnonymousUserSession());
 
     $this->form_state->set('example', $this->randomMachineName());
     \Drupal::formBuilder()->setCache($this->form_build_id, $this->form, $this->form_state);