diff --git a/core/modules/system/lib/Drupal/system/Controller/SystemController.php b/core/modules/system/lib/Drupal/system/Controller/SystemController.php
index bd71353..b261f19 100644
--- a/core/modules/system/lib/Drupal/system/Controller/SystemController.php
+++ b/core/modules/system/lib/Drupal/system/Controller/SystemController.php
@@ -7,17 +7,68 @@
 
 namespace Drupal\system\Controller;
 
+use Drupal\Component\Plugin\PluginManagerInterface;
 use Drupal\Component\Utility\Tags;
 use Drupal\Component\Utility\Unicode;
-use Symfony\Component\DependencyInjection\ContainerAware;
+use Drupal\Core\Controller\ControllerInterface;
+use Drupal\Core\Routing\PathBasedGeneratorInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\HttpFoundation\JsonResponse;
+use Symfony\Component\HttpFoundation\RedirectResponse;
 use Symfony\Component\HttpFoundation\Request;
 
-
 /**
  * Returns responses for System routes.
  */
-class SystemController extends ContainerAware {
+class SystemController implements ControllerInterface {
+
+  /**
+   * The plugin UI manager.
+   *
+   * @var \Drupal\Component\Plugin\PluginManagerInterface
+   */
+  protected $pluginUiManager;
+
+  /**
+   * The URL generator.
+   *
+   * @var \Drupal\Core\Routing\PathBasedGeneratorInterface
+   */
+  protected $urlGenerator;
+
+  /**
+   * The dependency injection container.
+   *
+   * @var \Symfony\Component\DependencyInjection\ContainerInterface
+   */
+  protected $container;
+
+  /**
+   * Constructs a new SystemController object.
+   *
+   * @param \Symfony\Component\DependencyInjection\ContainerInterface $container
+   *   The dependency injection container.
+   * @param \Drupal\Component\Plugin\PluginManagerInterface $plugin_ui_manager
+   *   The plugin UI manager.
+   * @param \Drupal\Core\Routing\PathBasedGeneratorInterface $url_generator
+   *   The URL generator.
+   */
+  public function __construct(ContainerInterface $container, PluginManagerInterface $plugin_ui_manager, PathBasedGeneratorInterface $url_generator) {
+    $this->container = $container;
+    $this->pluginUiManager = $plugin_ui_manager;
+    $this->urlGenerator = $url_generator;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static(
+      $container,
+      $container->get('plugin.manager.system.plugin_ui'),
+      $container->get('url_generator')
+    );
+  }
 
   /**
    * Autocompletes any plugin system tied to a plugin UI plugin.
@@ -41,7 +92,7 @@ public function autocomplete($plugin_id, Request $request) {
     $string = Unicode::strtolower(array_pop($string_typed));
     $matches = array();
     if ($string) {
-      $plugin_ui = $this->container->get('plugin.manager.system.plugin_ui')->getDefinition($plugin_id);
+      $plugin_ui = $this->pluginUiManager->getDefinition($plugin_id);
       $manager = $this->container->get($plugin_ui['manager']);
       $titles = array();
       foreach($manager->getDefinitions() as $plugin_id => $plugin) {
@@ -53,4 +104,17 @@ public function autocomplete($plugin_id, Request $request) {
     return new JsonResponse($matches);
   }
 
+  /**
+   * Sets whether the admin menu is in compact mode or not.
+   *
+   * @param string $mode
+   *   Valid values are 'on' and 'off'.
+   *
+   * @return \Symfony\Component\HttpFoundation\RedirectResponse
+   */
+  function compactPage($mode) {
+    user_cookie_save(array('admin_compact_mode' => ($mode == 'on')));
+    return new RedirectResponse(url('<front>', array('absolute' => TRUE)));
+  }
+
 }
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index c15f95d..91ea7e1 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -640,13 +640,6 @@ function system_menu() {
     'menu_name' => 'admin',
     'file' => 'system.admin.inc',
   );
-  $items['admin/compact'] = array(
-    'title' => 'Compact mode',
-    'page callback' => 'system_admin_compact_page',
-    'access arguments' => array('access administration pages'),
-    'type' => MENU_CALLBACK,
-    'file' => 'system.admin.inc',
-  );
   $items['admin/tasks'] = array(
     'title' => 'Tasks',
     'type' => MENU_DEFAULT_LOCAL_TASK,
@@ -3084,14 +3077,14 @@ function confirm_form($form, $question, $path, $description = NULL, $yes = NULL,
  * such as the configuration page and the permissions page.
  *
  * Whether the user is in compact mode is determined by a cookie, which is set
- * for the user by system_admin_compact_page().
+ * for the user by \Drupal\system\Controller\SystemController::compactPage().
  *
  * If the user does not have the cookie, the default value is given by the
  * system variable 'admin_compact_mode', which itself defaults to FALSE. This
  * does not have a user interface to set it: it is a hidden variable which can
  * be set in the settings.php file.
  *
- * @return
+ * @return bool
  *   TRUE when in compact mode, FALSE when in expanded mode.
  */
 function system_admin_compact_mode() {
@@ -3101,17 +3094,6 @@ function system_admin_compact_mode() {
 }
 
 /**
- * Menu callback; Sets whether the admin menu is in compact mode or not.
- *
- * @param $mode
- *   Valid values are 'on' and 'off'.
- */
-function system_admin_compact_page($mode = 'off') {
-  user_cookie_save(array('admin_compact_mode' => ($mode == 'on')));
-  return new RedirectResponse(url('<front>', array('absolute' => TRUE)));
-}
-
-/**
  * Generate a list of tasks offered by a specified module.
  *
  * @param $module
diff --git a/core/modules/system/system.routing.yml b/core/modules/system/system.routing.yml
index 144c8f9..ae37729 100644
--- a/core/modules/system/system.routing.yml
+++ b/core/modules/system/system.routing.yml
@@ -4,6 +4,15 @@ system.cron:
     _controller: '\Drupal\system\CronController::run'
   requirements:
     _access_system_cron: 'TRUE'
+
+system_admin_compact_page:
+  pattern: '/admin/compact/{mode}'
+  defaults:
+    _controller: 'Drupal\system\Controller\SystemController::compactPage'
+    mode: 'off'
+  requirements:
+    _permission: 'access administration pages'
+
 system.machine_name_transliterate:
   pattern: '/machine_name/transliterate'
   defaults: