diff --git a/core/scripts/run-tests.sh b/core/scripts/run-tests.sh
index 4e35b28..dd10b94 100644
--- a/core/scripts/run-tests.sh
+++ b/core/scripts/run-tests.sh
@@ -10,6 +10,8 @@
 use Drupal\Core\Site\Settings;
 use Drupal\Core\Test\TestRunnerKernel;
 use Symfony\Component\HttpFoundation\Request;
+use Symfony\Cmf\Component\Routing\RouteObjectInterface;
+use Symfony\Component\Routing\Route;
 
 $autoloader = require_once __DIR__ . '/../vendor/autoload.php';
 
@@ -32,7 +34,15 @@
 
 $request = Request::createFromGlobals();
 $kernel = TestRunnerKernel::createFromRequest($request, $autoloader);
-$kernel->prepareLegacyRequest($request);
+$kernel->boot();
+// Load all modules and perform request related initialization.
+$kernel->preHandle($request);
+
+// Initialize a route on this legacy request similar to
+// \Drupal\Core\DrupalKernel::prepareLegacyRequest() since normal routing
+// will not happen.
+$request->attributes->set(RouteObjectInterface::ROUTE_OBJECT, new Route('<none>'));
+$request->attributes->set(RouteObjectInterface::ROUTE_NAME, '<none>');
 
 if ($args['execute-test']) {
   simpletest_script_setup_database();