diff --git a/core/tests/Drupal/Tests/Core/StackMiddleware/RequestStackMiddlewareTest.php b/core/tests/Drupal/Tests/Core/StackMiddleware/RequestStackMiddlewareTest.php
index 3816480503..e4a3479ff5 100644
--- a/core/tests/Drupal/Tests/Core/StackMiddleware/RequestStackMiddlewareTest.php
+++ b/core/tests/Drupal/Tests/Core/StackMiddleware/RequestStackMiddlewareTest.php
@@ -5,7 +5,6 @@
 use Drupal\Core\Url;
 use Drupal\KernelTests\KernelTestBase;
 use Symfony\Component\HttpFoundation\Request;
-use Symfony\Component\HttpKernel\HttpKernelInterface;
 
 /**
  * Tests the usage of the request stack as part of request processing.
@@ -17,7 +16,7 @@ class RequestStackMiddlewareTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['httpkernel_test', 'system'];
+  protected static $modules = ['httpkernel_test', 'system'];
 
   /**
    * {@inheritdoc}
@@ -25,7 +24,6 @@ class RequestStackMiddlewareTest extends KernelTestBase {
   protected function setUp() {
     parent::setUp();
 
-    $this->installSchema('system', 'router');
     \Drupal::service('router.builder')->rebuild();
   }