diff --git a/core/modules/simpletest/src/WebTestBase.php b/core/modules/simpletest/src/WebTestBase.php
index d7ddacd..dc7853e 100644
--- a/core/modules/simpletest/src/WebTestBase.php
+++ b/core/modules/simpletest/src/WebTestBase.php
@@ -27,7 +27,7 @@
 use Drupal\Core\Url;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpFoundation\Request;
-use Symfony\Component\Yaml\Yaml;
+use Symfony\Component\Yaml\Yaml as SymfonyYaml;
 use Zend\Diactoros\Uri;
 
 /**
@@ -636,7 +636,7 @@ protected function prepareSettings() {
     copy($settings_services_file, $directory . '/services.yml');
     if ($this->strictConfigSchema) {
       // Add a listener to validate configuration schema on save.
-      $yaml = new Yaml();
+      $yaml = new SymfonyYaml();
       $content = file_get_contents($directory . '/services.yml');
       $services = $yaml->parse($content);
       $services['services']['simpletest.config_schema_checker'] = [
diff --git a/core/modules/simpletest/tests/src/Unit/TestInfoParsingTest.php b/core/modules/simpletest/tests/src/Unit/TestInfoParsingTest.php
index 6d814e8..9a69d78 100644
--- a/core/modules/simpletest/tests/src/Unit/TestInfoParsingTest.php
+++ b/core/modules/simpletest/tests/src/Unit/TestInfoParsingTest.php
@@ -3,10 +3,7 @@
 /**
  * @file
  * Contains \Drupal\Tests\simpletest\Unit\TestInfoParsingTest.
- */use 
-    \Drupal\simpletest\TestDiscovery;
-use Drupal\simpletest\TestDiscovery;
-
+ */
 
 namespace Drupal\Tests\simpletest\Unit {