diff --git a/core/modules/system/lib/Drupal/system/Controller/SystemInfoController.php b/core/modules/system/lib/Drupal/system/Controller/SystemInfoController.php
index 3bfad98..099d748 100644
--- a/core/modules/system/lib/Drupal/system/Controller/SystemInfoController.php
+++ b/core/modules/system/lib/Drupal/system/Controller/SystemInfoController.php
@@ -10,7 +10,6 @@
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpFoundation\Response;
 use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
-use Drupal\Core\Database\Connection;
 use Drupal\system\SystemManager;
 
 /**
diff --git a/core/modules/system/lib/Drupal/system/DateFormatListBuilder.php b/core/modules/system/lib/Drupal/system/DateFormatListBuilder.php
index 076a27c..53b31a5 100644
--- a/core/modules/system/lib/Drupal/system/DateFormatListBuilder.php
+++ b/core/modules/system/lib/Drupal/system/DateFormatListBuilder.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\system;
 
-use Drupal\Component\Utility\String;
 use Drupal\Core\Config\Entity\ConfigEntityListBuilder;
 use Drupal\Core\Datetime\Date;
 use Drupal\Core\Entity\EntityInterface;
diff --git a/core/modules/system/lib/Drupal/system/Entity/DateFormat.php b/core/modules/system/lib/Drupal/system/Entity/DateFormat.php
index fabab0e..a3d6ece 100644
--- a/core/modules/system/lib/Drupal/system/Entity/DateFormat.php
+++ b/core/modules/system/lib/Drupal/system/Entity/DateFormat.php
@@ -9,7 +9,6 @@
 
 use Drupal\Core\Config\Entity\ConfigEntityBase;
 use Drupal\Core\Datetime\DrupalDateTime;
-use Drupal\Core\Entity\EntityStorageInterface;
 use Drupal\system\DateFormatInterface;
 
 /**
diff --git a/core/modules/system/lib/Drupal/system/SystemConfigSubscriber.php b/core/modules/system/lib/Drupal/system/SystemConfigSubscriber.php
index 39f7b52..e582251 100644
--- a/core/modules/system/lib/Drupal/system/SystemConfigSubscriber.php
+++ b/core/modules/system/lib/Drupal/system/SystemConfigSubscriber.php
@@ -10,7 +10,6 @@
 use Drupal\Core\Config\ConfigEvents;
 use Drupal\Core\Config\ConfigImporterEvent;
 use Drupal\Core\Config\ConfigImporterException;
-use Drupal\Core\Config\StorageDispatcher;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 
 /**
diff --git a/core/modules/system/lib/Drupal/system/SystemManager.php b/core/modules/system/lib/Drupal/system/SystemManager.php
index 506e78c..6796f97 100644
--- a/core/modules/system/lib/Drupal/system/SystemManager.php
+++ b/core/modules/system/lib/Drupal/system/SystemManager.php
@@ -9,7 +9,6 @@
 use Drupal\Component\Utility\Unicode;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Symfony\Cmf\Component\Routing\RouteObjectInterface;
-use Symfony\Component\DependencyInjection\ContainerInterface;
 use Drupal\Core\Database\Connection;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Symfony\Component\HttpFoundation\Request;
diff --git a/core/modules/system/lib/Drupal/system/Tests/Ajax/DialogTest.php b/core/modules/system/lib/Drupal/system/Tests/Ajax/DialogTest.php
index fedefac..5261187 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Ajax/DialogTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Ajax/DialogTest.php
@@ -7,8 +7,6 @@
 
 namespace Drupal\system\Tests\Ajax;
 
-use Drupal\ajax_test\Form\AjaxTestForm;
-
 /**
  * Tests use of dialogs as wrappers for Ajax responses.
  */
diff --git a/core/modules/system/lib/Drupal/system/Tests/Cache/DatabaseBackendUnitTest.php b/core/modules/system/lib/Drupal/system/Tests/Cache/DatabaseBackendUnitTest.php
index 3b607a5..762ae86 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Cache/DatabaseBackendUnitTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Cache/DatabaseBackendUnitTest.php
@@ -8,7 +8,6 @@
 namespace Drupal\system\Tests\Cache;
 
 use Drupal\Core\Cache\DatabaseBackend;
-use Drupal\Core\Database\Database;
 
 /**
  * Tests DatabaseBackend using GenericCacheBackendUnitTestBase.
diff --git a/core/modules/system/lib/Drupal/system/Tests/Common/CascadingStylesheetsTest.php b/core/modules/system/lib/Drupal/system/Tests/Common/CascadingStylesheetsTest.php
index 5c016ce..97b1fc6 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Common/CascadingStylesheetsTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Common/CascadingStylesheetsTest.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\system\Tests\Common;
 
-use Drupal\Core\Language\Language;
 use Drupal\simpletest\DrupalUnitTestBase;
 
 /**
diff --git a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityValidationTest.php b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityValidationTest.php
index 1346c7f..09e1e54 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityValidationTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityValidationTest.php
@@ -7,11 +7,6 @@
 
 namespace Drupal\system\Tests\Entity;
 
-use Drupal\Core\Entity\EntityInterface;
-use Drupal\Core\Field\FieldItemListInterface;
-use Drupal\Core\Field\FieldItemInterface;
-use Drupal\Core\TypedData\TypedDataInterface;
-
 /**
  * Tests Entity API base functionality.
  */
diff --git a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityViewControllerTest.php b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityViewControllerTest.php
index e6d4971..102eeb7 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityViewControllerTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityViewControllerTest.php
@@ -8,7 +8,6 @@
 namespace Drupal\system\Tests\Entity;
 
 use Drupal\simpletest\WebTestBase;
-use Drupal\Core\Language\Language;
 
 /**
  * Tests \Drupal\Core\Entity\Controller\EntityViewController.
diff --git a/core/modules/system/lib/Drupal/system/Tests/Form/SystemConfigFormTest.php b/core/modules/system/lib/Drupal/system/Tests/Form/SystemConfigFormTest.php
index 211d1be..1b6d99d 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Form/SystemConfigFormTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Form/SystemConfigFormTest.php
@@ -8,7 +8,6 @@
 namespace Drupal\system\Tests\Form;
 
 use Drupal\simpletest\WebTestBase;
-use Drupal\form_test\SystemConfigFormTestForm;
 
 /**
  * Tests the SystemConfigFormTestBase class.
diff --git a/core/modules/system/lib/Drupal/system/Tests/ParamConverter/UpcastingTest.php b/core/modules/system/lib/Drupal/system/Tests/ParamConverter/UpcastingTest.php
index 31d0a0f..75152e0 100644
--- a/core/modules/system/lib/Drupal/system/Tests/ParamConverter/UpcastingTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/ParamConverter/UpcastingTest.php
@@ -7,9 +7,6 @@
 
 namespace Drupal\system\Tests\ParamConverter;
 
-use Symfony\Component\HttpFoundation\Request;
-use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
-use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\simpletest\WebTestBase;
 
 /**
diff --git a/core/modules/system/lib/Drupal/system/Tests/Plugin/AlterDecoratorTest.php b/core/modules/system/lib/Drupal/system/Tests/Plugin/AlterDecoratorTest.php
index ce35689..552934e 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Plugin/AlterDecoratorTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Plugin/AlterDecoratorTest.php
@@ -7,9 +7,7 @@
 
 namespace Drupal\system\Tests\Plugin;
 
-use Drupal\Component\Plugin\Exception\ExceptionInterface;
 use Drupal\plugin_test\Plugin\AlterDecoratorTestPluginManager;
-use Drupal\plugin_test\Plugin\TestPluginManager;
 use Drupal\simpletest\WebTestBase;
 
 /**
diff --git a/core/modules/system/lib/Drupal/system/Tests/Plugin/CacheDecoratorTest.php b/core/modules/system/lib/Drupal/system/Tests/Plugin/CacheDecoratorTest.php
index 532fea8..aa09289 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Plugin/CacheDecoratorTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Plugin/CacheDecoratorTest.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\system\Tests\Plugin;
 
-use Drupal\Core\Cache\MemoryBackendFactory;
 use Drupal\Core\Cache\MemoryBackend;
 use Drupal\system\Tests\Plugin\Discovery\DiscoveryTestBase;
 use Drupal\Component\Plugin\Discovery\StaticDiscovery;
diff --git a/core/modules/system/lib/Drupal/system/Tests/Plugin/ContextPluginTest.php b/core/modules/system/lib/Drupal/system/Tests/Plugin/ContextPluginTest.php
index 6f3bd49..748487e 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Plugin/ContextPluginTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Plugin/ContextPluginTest.php
@@ -10,7 +10,6 @@
 use Drupal\simpletest\DrupalUnitTestBase;
 use Drupal\plugin_test\Plugin\MockBlockManager;
 use Drupal\Component\Plugin\Exception\PluginException;
-use Drupal\Component\Plugin\Exception\ContextException;
 
 /**
  * Tests that context aware plugins function correctly.
diff --git a/core/modules/system/lib/Drupal/system/Tests/Routing/RouterTest.php b/core/modules/system/lib/Drupal/system/Tests/Routing/RouterTest.php
index f4dadae..a9e4598 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Routing/RouterTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Routing/RouterTest.php
@@ -8,7 +8,6 @@
 namespace Drupal\system\Tests\Routing;
 
 use Drupal\simpletest\WebTestBase;
-use Symfony\Component\Routing\RequestContext;
 
 /**
  * Functional class for the full integrated routing system.
diff --git a/core/modules/system/lib/Drupal/system/Tests/System/CronQueueTest.php b/core/modules/system/lib/Drupal/system/Tests/System/CronQueueTest.php
index c62d519..2bbd872 100644
--- a/core/modules/system/lib/Drupal/system/Tests/System/CronQueueTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/System/CronQueueTest.php
@@ -7,10 +7,6 @@
 
 namespace Drupal\system\Tests\System;
 
-use Drupal\Core\Database\Database;
-use Drupal\Core\Queue\DatabaseQueue;
-use Drupal\Core\Queue\Memory;
-use Drupal\simpletest\DrupalUnitTestBase;
 use Drupal\simpletest\WebTestBase;
 
 /**
diff --git a/core/modules/system/lib/Drupal/system/Tests/System/DateFormatsMachineNameTest.php b/core/modules/system/lib/Drupal/system/Tests/System/DateFormatsMachineNameTest.php
index da2fa0b..495ab87 100644
--- a/core/modules/system/lib/Drupal/system/Tests/System/DateFormatsMachineNameTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/System/DateFormatsMachineNameTest.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\system\Tests\System;
 
-use Drupal\Component\Datetime\DateTimePlus;
 use Drupal\Component\Utility\Unicode;
 use Drupal\simpletest\WebTestBase;
 
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index 9ab9bd5..ad8c084 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -5,19 +5,13 @@
  * Configuration system that lets administrators modify the workings of the site.
  */
 
-use Drupal\Core\Cache\CacheBackendInterface;
 use Drupal\Core\Cache\Cache;
 use Drupal\Core\Language\Language;
 use Drupal\Core\Extension\Extension;
 use Drupal\Core\Extension\ExtensionDiscovery;
-use Drupal\Core\Utility\ModuleInfo;
 use Drupal\block\BlockPluginInterface;
-use Drupal\menu_link\MenuLinkInterface;
 use Drupal\user\UserInterface;
-use Symfony\Component\HttpFoundation\JsonResponse;
 use Symfony\Component\HttpFoundation\RedirectResponse;
-use Symfony\Component\HttpFoundation\Response;
-use Symfony\Component\HttpFoundation\Request;
 use Guzzle\Http\Exception\BadResponseException;
 use Guzzle\Http\Exception\RequestException;
 
diff --git a/core/modules/system/tests/Drupal/system/Tests/Transliteration/MachineNameControllerTest.php b/core/modules/system/tests/Drupal/system/Tests/Transliteration/MachineNameControllerTest.php
index 8eb2592..fddac33 100644
--- a/core/modules/system/tests/Drupal/system/Tests/Transliteration/MachineNameControllerTest.php
+++ b/core/modules/system/tests/Drupal/system/Tests/Transliteration/MachineNameControllerTest.php
@@ -8,7 +8,6 @@
 namespace Drupal\system\Tests\Transliteration;
 
 use Drupal\Tests\UnitTestCase;
-use Drupal\Core\DependencyInjection\ContainerBuilder;
 use Drupal\Component\Transliteration\PHPTransliteration;
 use Drupal\system\MachineNameController;
 use Symfony\Component\HttpFoundation\Request;
diff --git a/core/modules/system/tests/modules/entity_test/lib/Drupal/entity_test/Entity/EntityTest.php b/core/modules/system/tests/modules/entity_test/lib/Drupal/entity_test/Entity/EntityTest.php
index a8f7191..653d27a 100644
--- a/core/modules/system/tests/modules/entity_test/lib/Drupal/entity_test/Entity/EntityTest.php
+++ b/core/modules/system/tests/modules/entity_test/lib/Drupal/entity_test/Entity/EntityTest.php
@@ -11,7 +11,6 @@
 use Drupal\Core\Entity\EntityTypeInterface;
 use Drupal\Core\Field\FieldDefinition;
 use Drupal\Core\Entity\EntityStorageInterface;
-use Drupal\Core\Language\Language;
 use Drupal\user\EntityOwnerInterface;
 use Drupal\user\UserInterface;
 
diff --git a/core/modules/system/tests/modules/entity_test/lib/Drupal/entity_test/Entity/EntityTestCache.php b/core/modules/system/tests/modules/entity_test/lib/Drupal/entity_test/Entity/EntityTestCache.php
index 4df9ecf..8480d80 100644
--- a/core/modules/system/tests/modules/entity_test/lib/Drupal/entity_test/Entity/EntityTestCache.php
+++ b/core/modules/system/tests/modules/entity_test/lib/Drupal/entity_test/Entity/EntityTestCache.php
@@ -7,8 +7,6 @@
 
 namespace Drupal\entity_test\Entity;
 
-use Drupal\Core\Language\Language;
-
 /**
  * Defines the test entity class.
  *
diff --git a/core/modules/system/tests/modules/form_test/form_test.module b/core/modules/system/tests/modules/form_test/form_test.module
index 939dc83..2c750ab 100644
--- a/core/modules/system/tests/modules/form_test/form_test.module
+++ b/core/modules/system/tests/modules/form_test/form_test.module
@@ -6,12 +6,9 @@
  */
 
 use Drupal\Component\Utility\Json;
-use Drupal\Core\Database\Connection;
 use Drupal\Core\Database\Database;
 use Drupal\Core\Language\Language;
 use Drupal\form_test\Callbacks;
-use Drupal\form_test\FormTestObject;
-use Drupal\form_test\SystemConfigFormTestForm;
 use Drupal\Core\Datetime\DrupalDateTime;
 use Symfony\Component\HttpFoundation\JsonResponse;
 
diff --git a/core/modules/system/tests/modules/menu_test/lib/Drupal/menu_test/EventSubscriber/ActiveTrailSubscriber.php b/core/modules/system/tests/modules/menu_test/lib/Drupal/menu_test/EventSubscriber/ActiveTrailSubscriber.php
index 04c79c1..5b63e55 100644
--- a/core/modules/system/tests/modules/menu_test/lib/Drupal/menu_test/EventSubscriber/ActiveTrailSubscriber.php
+++ b/core/modules/system/tests/modules/menu_test/lib/Drupal/menu_test/EventSubscriber/ActiveTrailSubscriber.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\menu_test\EventSubscriber;
 
-use Drupal\Core\KeyValueStore\KeyValueStoreInterface;
 use Drupal\Core\KeyValueStore\StateInterface;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Symfony\Component\HttpKernel\Event\GetResponseEvent;
diff --git a/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/TestPluginManager.php b/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/TestPluginManager.php
index 85fabeb..adffdef 100644
--- a/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/TestPluginManager.php
+++ b/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/TestPluginManager.php
@@ -9,7 +9,6 @@
 
 use Drupal\Component\Plugin\PluginManagerBase;
 use Drupal\Component\Plugin\Discovery\StaticDiscovery;
-use Drupal\Component\Plugin\Discovery\DerivativeDiscoveryDecorator;
 use Drupal\Component\Plugin\Factory\DefaultFactory;
 
 /**
diff --git a/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/plugin_test/mock_block/MockUserNameBlock.php b/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/plugin_test/mock_block/MockUserNameBlock.php
index 3fc1f84..9150167 100644
--- a/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/plugin_test/mock_block/MockUserNameBlock.php
+++ b/core/modules/system/tests/modules/plugin_test/lib/Drupal/plugin_test/Plugin/plugin_test/mock_block/MockUserNameBlock.php
@@ -8,7 +8,6 @@
 namespace Drupal\plugin_test\Plugin\plugin_test\mock_block;
 
 use Drupal\Core\Plugin\ContextAwarePluginBase;
-use Drupal\Component\Plugin\Discovery\DiscoveryInterface;
 
 /**
  * Implementation of a user name block plugin used by Plugin API context test.
