diff --git a/core/core.services.yml b/core/core.services.yml
index cf68e70..049aae2 100644
--- a/core/core.services.yml
+++ b/core/core.services.yml
@@ -1203,7 +1203,6 @@ services:
   theme.negotiator_subscriber:
     class: Drupal\Core\EventSubscriber\ThemeNegotiatorSubscriber
     parent: container.trait
-    arguments: ['@theme.negotiator']
     tags:
       - { name: event_subscriber }
   authentication:
diff --git a/core/lib/Drupal/Core/DependencyInjection/Compiler/RegisterThemeNegotiators.php b/core/lib/Drupal/Core/DependencyInjection/Compiler/RegisterThemeNegotiators.php
index ff9b828..7cf3b21 100644
--- a/core/lib/Drupal/Core/DependencyInjection/Compiler/RegisterThemeNegotiators.php
+++ b/core/lib/Drupal/Core/DependencyInjection/Compiler/RegisterThemeNegotiators.php
@@ -28,6 +28,10 @@ public function process(ContainerBuilder $container) {
     $container
       ->getDefinition('theme.negotiator')
       ->addArgument($service_ids);
+
+    $container
+      ->getDefinition('theme.negotiator_subscriber')
+      ->addArgument($service_ids);
   }
 
 }
diff --git a/core/lib/Drupal/Core/EventSubscriber/ThemeNegotiatorSubscriber.php b/core/lib/Drupal/Core/EventSubscriber/ThemeNegotiatorSubscriber.php
index 7eabaac..d2ee005 100644
--- a/core/lib/Drupal/Core/EventSubscriber/ThemeNegotiatorSubscriber.php
+++ b/core/lib/Drupal/Core/EventSubscriber/ThemeNegotiatorSubscriber.php
@@ -10,7 +10,6 @@
 use Drupal\Core\Routing\RouteBuildEvent;
 use Drupal\Core\Routing\RouteMatch;
 use Drupal\Core\Routing\RoutingEvents;
-use Drupal\Core\Theme\ThemeNegotiator;
 use Symfony\Component\DependencyInjection\ContainerAwareInterface;
 use Symfony\Component\DependencyInjection\ContainerAwareTrait;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
@@ -22,34 +21,32 @@ class ThemeNegotiatorSubscriber implements EventSubscriberInterface, ContainerAw
 
   use ContainerAwareTrait;
 
-  /**
-   * @var ThemeNegotiator
-   */
-  protected $theme_negotiator;
+  protected $service_ids;
 
   /**
    * Constructs the ThemeNegotiatorSubscriber object.
    */
-  public function __construct($theme_negotiator) {
-    $this->theme_negotiator = $theme_negotiator;
+  public function __construct($service_ids) {
+    // Sort the negotiators by priority.
+    arsort($service_ids);
+    $this->service_ids = array_keys($service_ids);
   }
 
   /**
    */
   public function onRouteAlter(RouteBuildEvent $event) {
-    $all_negotiators = $this->theme_negotiator->getSortedNegotiators();
-
     foreach ($event->getRouteCollection() as $route_name => $route) {
-      $route_negotiators = [];
-      foreach ($all_negotiators as $service_id) {
+      $service_ids = [];
+      foreach ($this->service_ids as $service_id) {
         /** @var \Drupal\Core\Theme\ThemeNegotiator $theme_negotiator */
+        $route_match = new RouteMatch($route_name, $route);
         $theme_negotiator = $this->container->get($service_id);
-        if ($theme_negotiator->applies($route_name, $route)) {
-          $route_negotiators[] = $service_id;
+        if ($theme_negotiator->applies($route_match, $route)) {
+          $service_ids[] = $service_id;
         }
       }
-      if ($route_negotiators) {
-        $route->setOption('_theme_negotiators', array_unique($route_negotiators));
+      if ($service_ids) {
+        $route->setOption('_theme_negotiators', array_unique($service_ids));
       }
     }
   }
diff --git a/core/lib/Drupal/Core/Theme/AjaxBasePageNegotiator.php b/core/lib/Drupal/Core/Theme/AjaxBasePageNegotiator.php
index eec59af..7e76cff 100644
--- a/core/lib/Drupal/Core/Theme/AjaxBasePageNegotiator.php
+++ b/core/lib/Drupal/Core/Theme/AjaxBasePageNegotiator.php
@@ -72,7 +72,7 @@ public function __construct(CsrfTokenGenerator $token_generator, ConfigFactoryIn
   /**
    * {@inheritdoc}
    */
-  public function applies($route_name = '', Route $route = NULL) {
+  public function applies($route_name, Route $route) {
     // Check whether the route was configured to use the base page theme.
     return $route
       && $route->hasOption('_theme')
diff --git a/core/lib/Drupal/Core/Theme/DefaultNegotiator.php b/core/lib/Drupal/Core/Theme/DefaultNegotiator.php
index 83f9e78..8a57019 100644
--- a/core/lib/Drupal/Core/Theme/DefaultNegotiator.php
+++ b/core/lib/Drupal/Core/Theme/DefaultNegotiator.php
@@ -36,7 +36,7 @@ public function __construct(ConfigFactoryInterface $config_factory) {
   /**
    * {@inheritdoc}
    */
-  public function applies($route_name = '', Route $route = NULL) {
+  public function applies($route_name, Route $route) {
     return TRUE;
   }
 
diff --git a/core/lib/Drupal/Core/Theme/ThemeNegotiator.php b/core/lib/Drupal/Core/Theme/ThemeNegotiator.php
index 1008f64..358013d 100644
--- a/core/lib/Drupal/Core/Theme/ThemeNegotiator.php
+++ b/core/lib/Drupal/Core/Theme/ThemeNegotiator.php
@@ -26,34 +26,42 @@ class ThemeNegotiator implements ThemeNegotiatorInterface, ContainerAwareInterfa
   use ContainerAwareTrait;
 
   /**
+   * Holds arrays of theme negotiators, keyed by priority.
+   *
+   * @var array
+   */
+  protected $negotiators = array();
+
+  /**
+   * Holds the array of theme negotiators sorted by priority.
+   *
+   * Set to NULL if the array needs to be re-calculated.
+   *
+   * @var array|NULL
+   */
+  protected $sortedNegotiators;
+
+  /**
    * The access checker for themes.
    *
    * @var \Drupal\Core\Theme\ThemeAccessCheck
    */
   protected $themeAccess;
 
-  protected $negotiator_service_ids;
-
   /**
    * Constructs a new ThemeNegotiator.
    *
    * @param \Drupal\Core\Theme\ThemeAccessCheck $theme_access
    *   The access checker for themes.
    */
-  public function __construct(ThemeAccessCheck $theme_access, $negotiator_service_ids) {
+  public function __construct(ThemeAccessCheck $theme_access) {
     $this->themeAccess = $theme_access;
-    arsort($negotiator_service_ids);
-    $this->negotiator_service_ids = array_keys($negotiator_service_ids);
-  }
-
-  public function getSortedNegotiators() {
-    return $this->negotiator_service_ids;
   }
 
   /**
    * {@inheritdoc}
    */
-  public function applies($route_name = '', Route $route = NULL) {
+  public function applies($route_name, Route $route) {
     return TRUE;
   }
 
@@ -61,19 +69,12 @@ public function applies($route_name = '', Route $route = NULL) {
    * {@inheritdoc}
    */
   public function determineActiveTheme(RouteMatchInterface $route_match) {
-    $route = $route_match->getRouteObject() ?: Null;
-
-    // If no route was found (for example on a 404 page), we still need to
-    // evaluate all available theme negotiators.
-    $negotiator_service_ids = !empty($route) ? $route->getOption('_theme_negotiators') : $this->negotiator_service_ids;
-
-    foreach ($negotiator_service_ids as $service_id) {
+    $route = $route_match->getRouteObject();
+    foreach ($route->getOption('_theme_negotiators') as $service_id) {
       $negotiator = $this->container->get($service_id);
-      if (!empty($route) || $negotiator->applies($route_match->getRouteName(), $route)) {
-        $theme = $negotiator->determineActiveTheme($route_match);
-        if ($theme !== NULL && $this->themeAccess->checkAccess($theme)) {
-          return $theme;
-        }
+      $theme = $negotiator->determineActiveTheme($route_match);
+      if ($theme !== NULL && $this->themeAccess->checkAccess($theme)) {
+        return $theme;
       }
     }
   }
diff --git a/core/lib/Drupal/Core/Theme/ThemeNegotiatorInterface.php b/core/lib/Drupal/Core/Theme/ThemeNegotiatorInterface.php
index a4346b8..d59f8dd 100644
--- a/core/lib/Drupal/Core/Theme/ThemeNegotiatorInterface.php
+++ b/core/lib/Drupal/Core/Theme/ThemeNegotiatorInterface.php
@@ -40,7 +40,7 @@
    *   TRUE if this negotiator should be used or FALSE to let other negotiators
    *   decide.
    */
-  public function applies($route_name = '', Route $route = NULL);
+  public function applies($route_name, Route $route);
 
   /**
    * Determine the active theme for the request.
diff --git a/core/modules/block/src/Theme/AdminDemoNegotiator.php b/core/modules/block/src/Theme/AdminDemoNegotiator.php
index 8796704..fc0e820 100644
--- a/core/modules/block/src/Theme/AdminDemoNegotiator.php
+++ b/core/modules/block/src/Theme/AdminDemoNegotiator.php
@@ -19,7 +19,7 @@ class AdminDemoNegotiator implements ThemeNegotiatorInterface {
   /**
    * {@inheritdoc}
    */
-  public function applies($route_name = '', Route $route = NULL) {
+  public function applies($route_name, Route $route) {
     return $route_name == 'block.admin_demo';
   }
 
diff --git a/core/modules/system/src/Theme/BatchNegotiator.php b/core/modules/system/src/Theme/BatchNegotiator.php
index 2b5d636..f1156a3 100644
--- a/core/modules/system/src/Theme/BatchNegotiator.php
+++ b/core/modules/system/src/Theme/BatchNegotiator.php
@@ -48,7 +48,7 @@ public function __construct(BatchStorageInterface $batch_storage, RequestStack $
   /**
    * {@inheritdoc}
    */
-  public function applies($route_name = '', Route $route = NULL) {
+  public function applies($route_name, Route $route) {
     return $route_name == 'system.batch_page';
   }
 
diff --git a/core/modules/system/src/Theme/DbUpdateNegotiator.php b/core/modules/system/src/Theme/DbUpdateNegotiator.php
index cc62c8c..e884e08 100644
--- a/core/modules/system/src/Theme/DbUpdateNegotiator.php
+++ b/core/modules/system/src/Theme/DbUpdateNegotiator.php
@@ -38,7 +38,7 @@ public function __construct(ConfigFactoryInterface $config_factory) {
   /**
    * {@inheritdoc}
    */
-  public function applies($route_name = '', Route $route = NULL) {
+  public function applies($route_name, Route $route) {
     return $route_name == 'system.db_update';
   }
 
diff --git a/core/modules/system/tests/modules/menu_test/src/Theme/TestThemeNegotiator.php b/core/modules/system/tests/modules/menu_test/src/Theme/TestThemeNegotiator.php
index 568fe1e..2d6c2c4 100644
--- a/core/modules/system/tests/modules/menu_test/src/Theme/TestThemeNegotiator.php
+++ b/core/modules/system/tests/modules/menu_test/src/Theme/TestThemeNegotiator.php
@@ -22,7 +22,7 @@ class TestThemeNegotiator implements ThemeNegotiatorInterface {
   /**
    * {@inheritdoc}
    */
-  public function applies($route_name = '', Route $route = NULL) {
+  public function applies($route_name, Route $route) {
     return (bool) $route_match->getParameter('inherited');
   }
 
diff --git a/core/modules/system/tests/modules/theme_test/src/Theme/CustomThemeNegotiator.php b/core/modules/system/tests/modules/theme_test/src/Theme/CustomThemeNegotiator.php
index 33af05a..f1fcdac 100644
--- a/core/modules/system/tests/modules/theme_test/src/Theme/CustomThemeNegotiator.php
+++ b/core/modules/system/tests/modules/theme_test/src/Theme/CustomThemeNegotiator.php
@@ -19,7 +19,7 @@ class CustomThemeNegotiator implements ThemeNegotiatorInterface {
   /**
    * {@inheritdoc}
    */
-  public function applies($route_name = '', Route $route = NULL) {
+  public function applies($route_name, Route $route) {
     return ($route && $route->hasOption('_custom_theme'));
   }
 
diff --git a/core/modules/system/tests/modules/theme_test/src/Theme/HighPriorityThemeNegotiator.php b/core/modules/system/tests/modules/theme_test/src/Theme/HighPriorityThemeNegotiator.php
index 1081355..0890492 100644
--- a/core/modules/system/tests/modules/theme_test/src/Theme/HighPriorityThemeNegotiator.php
+++ b/core/modules/system/tests/modules/theme_test/src/Theme/HighPriorityThemeNegotiator.php
@@ -19,8 +19,8 @@ class HighPriorityThemeNegotiator implements ThemeNegotiatorInterface {
   /**
    * {@inheritdoc}
    */
-  public function applies($route_name = '', Route $route = NULL) {
-    return ($route_name == 'theme_test.priority');
+  public function applies($route_name, Route $match) {
+    return ($route_match->getRouteName() == 'theme_test.priority');
   }
 
   /**
diff --git a/core/modules/user/src/Theme/AdminNegotiator.php b/core/modules/user/src/Theme/AdminNegotiator.php
index b7ac061..0db6e9c 100644
--- a/core/modules/user/src/Theme/AdminNegotiator.php
+++ b/core/modules/user/src/Theme/AdminNegotiator.php
@@ -68,7 +68,7 @@ public function __construct(AccountInterface $user, ConfigFactoryInterface $conf
   /**
    * {@inheritdoc}
    */
-  public function applies($route_name = '', Route $route = NULL) {
+  public function applies($route_name, Route $route) {
     return ($this->entityManager->hasHandler('user_role', 'storage') && $this->adminContext->isAdminRoute($route));
   }