diff --git a/core/lib/Drupal/Core/Access/AccessInterface.php b/core/lib/Drupal/Core/Access/AccessInterface.php
index 2bce73e..4e8b885 100644
--- a/core/lib/Drupal/Core/Access/AccessInterface.php
+++ b/core/lib/Drupal/Core/Access/AccessInterface.php
@@ -44,18 +44,18 @@
   /**
    * Checks for access to a route.
    *
-   * @param \Drupal\Core\Session\AccountInterface $account
-   *   The currently logged in account.
    * @param \Symfony\Component\Routing\Route $route
    *   The route to check against.
    * @param \Symfony\Component\HttpFoundation\Request $request
    *   The request object.
+   * @param \Drupal\Core\Session\AccountInterface $account
+   *   (optional) The currently logged in account.
    *
    * @return mixed
    *   TRUE if access is allowed.
    *   FALSE if not.
    *   NULL if no opinion.
    */
-  public function access(AccountInterface $account, Route $route, Request $request);
+  public function access(Route $route, Request $request, AccountInterface $account = NULL);
 
 }
diff --git a/core/lib/Drupal/Core/Access/AccessManager.php b/core/lib/Drupal/Core/Access/AccessManager.php
index 491b39b..c81b534 100644
--- a/core/lib/Drupal/Core/Access/AccessManager.php
+++ b/core/lib/Drupal/Core/Access/AccessManager.php
@@ -157,7 +157,7 @@ protected function checkAll(array $checks, Route $route, Request $request) {
       }
 
       $account = $request->attributes->get('account');
-      $service_access = $this->checks[$service_id]->access($account, $route, $request);
+      $service_access = $this->checks[$service_id]->access($route, $request, $account);
       if ($service_access === AccessInterface::ALLOW) {
         $access = TRUE;
       }
@@ -194,7 +194,7 @@ protected function checkAny(array $checks, $route, $request) {
       }
 
       $account = $request->attributes->get('account');
-      $service_access = $this->checks[$service_id]->access($account, $route, $request);
+      $service_access = $this->checks[$service_id]->access($route, $request, $account);
       if ($service_access === AccessInterface::ALLOW) {
         $access = TRUE;
       }
diff --git a/core/lib/Drupal/Core/Access/DefaultAccessCheck.php b/core/lib/Drupal/Core/Access/DefaultAccessCheck.php
index d949606..21a6c11 100644
--- a/core/lib/Drupal/Core/Access/DefaultAccessCheck.php
+++ b/core/lib/Drupal/Core/Access/DefaultAccessCheck.php
@@ -26,7 +26,7 @@ public function appliesTo() {
   /**
    * {@inheritdoc}
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     if ($route->getRequirement('_access') === 'TRUE') {
       return static::ALLOW;
     }
diff --git a/core/lib/Drupal/Core/Entity/EntityAccessCheck.php b/core/lib/Drupal/Core/Entity/EntityAccessCheck.php
index fcf558f..1fb4637 100644
--- a/core/lib/Drupal/Core/Entity/EntityAccessCheck.php
+++ b/core/lib/Drupal/Core/Entity/EntityAccessCheck.php
@@ -38,7 +38,7 @@ public function appliesTo() {
    * @endcode
    * Available operations are 'view', 'update', 'create', and 'delete'.
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     // Split the entity type and the operation.
     $requirement = $route->getRequirement('_entity_access');
     list($entity_type, $operation) = explode('.', $requirement);
diff --git a/core/lib/Drupal/Core/Entity/EntityCreateAccessCheck.php b/core/lib/Drupal/Core/Entity/EntityCreateAccessCheck.php
index 709a7aa..f7156f0 100644
--- a/core/lib/Drupal/Core/Entity/EntityCreateAccessCheck.php
+++ b/core/lib/Drupal/Core/Entity/EntityCreateAccessCheck.php
@@ -51,7 +51,7 @@ public function appliesTo() {
   /**
    * {@inheritdoc}
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     list($entity_type, $bundle) = explode(':', $route->getRequirement($this->requirementsKey) . ':');
     return $this->entityManager->getAccessController($entity_type)->createAccess($bundle, $account);
   }
diff --git a/core/modules/aggregator/lib/Drupal/aggregator/Access/CategoriesAccessCheck.php b/core/modules/aggregator/lib/Drupal/aggregator/Access/CategoriesAccessCheck.php
index a149ce1..4b02b5d 100644
--- a/core/modules/aggregator/lib/Drupal/aggregator/Access/CategoriesAccessCheck.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Access/CategoriesAccessCheck.php
@@ -45,7 +45,7 @@ public function appliesTo() {
   /**
    * {@inheritdoc}
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     return $account->hasPermission('access news feeds') && (bool) $this->database->queryRange('SELECT 1 FROM {aggregator_category}', 0, 1)->fetchField();
   }
 
diff --git a/core/modules/block/lib/Drupal/block/Access/BlockThemeAccessCheck.php b/core/modules/block/lib/Drupal/block/Access/BlockThemeAccessCheck.php
index 946367d..b43dcc4 100644
--- a/core/modules/block/lib/Drupal/block/Access/BlockThemeAccessCheck.php
+++ b/core/modules/block/lib/Drupal/block/Access/BlockThemeAccessCheck.php
@@ -27,7 +27,7 @@ public function appliesTo() {
   /**
    * {@inheritdoc}
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     $theme = $request->attributes->get('theme');
     return $account->hasPermission('administer blocks') && drupal_theme_access($theme);
   }
diff --git a/core/modules/edit/lib/Drupal/edit/Access/EditEntityAccessCheck.php b/core/modules/edit/lib/Drupal/edit/Access/EditEntityAccessCheck.php
index 8d469ff..f91671e 100644
--- a/core/modules/edit/lib/Drupal/edit/Access/EditEntityAccessCheck.php
+++ b/core/modules/edit/lib/Drupal/edit/Access/EditEntityAccessCheck.php
@@ -30,7 +30,7 @@ public function appliesTo() {
   /**
    * {@inheritdoc}
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     // @todo Request argument validation and object loading should happen
     //   elsewhere in the request processing pipeline:
     //   http://drupal.org/node/1798214.
diff --git a/core/modules/edit/lib/Drupal/edit/Access/EditEntityFieldAccessCheck.php b/core/modules/edit/lib/Drupal/edit/Access/EditEntityFieldAccessCheck.php
index 9d00d0c..6db45cf 100644
--- a/core/modules/edit/lib/Drupal/edit/Access/EditEntityFieldAccessCheck.php
+++ b/core/modules/edit/lib/Drupal/edit/Access/EditEntityFieldAccessCheck.php
@@ -30,7 +30,7 @@ public function appliesTo() {
   /**
    * {@inheritdoc}
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     // @todo Request argument validation and object loading should happen
     //   elsewhere in the request processing pipeline:
     //   http://drupal.org/node/1798214.
diff --git a/core/modules/field_ui/lib/Drupal/field_ui/Access/FormModeAccessCheck.php b/core/modules/field_ui/lib/Drupal/field_ui/Access/FormModeAccessCheck.php
index 965bc5d..75f5f81 100644
--- a/core/modules/field_ui/lib/Drupal/field_ui/Access/FormModeAccessCheck.php
+++ b/core/modules/field_ui/lib/Drupal/field_ui/Access/FormModeAccessCheck.php
@@ -27,7 +27,7 @@ public function appliesTo() {
   /**
    * {@inheritdoc}
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     if ($entity_type = $request->attributes->get('entity_type')) {
       $bundle = $request->attributes->get('bundle');
       $form_mode = $request->attributes->get('mode');
diff --git a/core/modules/field_ui/lib/Drupal/field_ui/Access/ViewModeAccessCheck.php b/core/modules/field_ui/lib/Drupal/field_ui/Access/ViewModeAccessCheck.php
index 3235eaf..fd620be 100644
--- a/core/modules/field_ui/lib/Drupal/field_ui/Access/ViewModeAccessCheck.php
+++ b/core/modules/field_ui/lib/Drupal/field_ui/Access/ViewModeAccessCheck.php
@@ -27,7 +27,7 @@ public function appliesTo() {
   /**
    * {@inheritdoc}
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     if ($entity_type = $request->attributes->get('entity_type')) {
       $bundle = $request->attributes->get('bundle');
       $view_mode = $request->attributes->get('mode');
diff --git a/core/modules/filter/lib/Drupal/filter/Access/FilterAccessCheck.php b/core/modules/filter/lib/Drupal/filter/Access/FilterAccessCheck.php
index c56c3a1..5c674fc 100644
--- a/core/modules/filter/lib/Drupal/filter/Access/FilterAccessCheck.php
+++ b/core/modules/filter/lib/Drupal/filter/Access/FilterAccessCheck.php
@@ -27,7 +27,7 @@ public function appliesTo() {
   /**
    * {@inheritdoc}
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     if ($format = $request->attributes->get('filter_format')) {
       // Handle special cases up front. All users have access to the fallback
       // format.
diff --git a/core/modules/filter/lib/Drupal/filter/Access/FormatDisableCheck.php b/core/modules/filter/lib/Drupal/filter/Access/FormatDisableCheck.php
index f299370..67befb0 100644
--- a/core/modules/filter/lib/Drupal/filter/Access/FormatDisableCheck.php
+++ b/core/modules/filter/lib/Drupal/filter/Access/FormatDisableCheck.php
@@ -27,7 +27,7 @@ public function appliesTo() {
   /**
    * Implements \Drupal\Core\Access\AccessCheckInterface::access().
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     if ($format = $request->attributes->get('filter_format')) {
       return $account->hasPermission('administer filters') && ($format->format != filter_fallback_format());
     }
diff --git a/core/modules/menu/lib/Drupal/menu/Access/DeleteLinkAccessCheck.php b/core/modules/menu/lib/Drupal/menu/Access/DeleteLinkAccessCheck.php
index 6ae396d..a274cb4 100644
--- a/core/modules/menu/lib/Drupal/menu/Access/DeleteLinkAccessCheck.php
+++ b/core/modules/menu/lib/Drupal/menu/Access/DeleteLinkAccessCheck.php
@@ -27,7 +27,7 @@ public function appliesTo() {
   /**
    * {@inheritdoc}
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     if ($account->hasPermission('administer menu') && $menu_link = $request->attributes->get('menu_link')) {
       // Links defined via hook_menu may not be deleted. Updated items are an
       // exception, as they can be broken.
diff --git a/core/modules/menu/lib/Drupal/menu/Access/DeleteMenuAccessCheck.php b/core/modules/menu/lib/Drupal/menu/Access/DeleteMenuAccessCheck.php
index 78cc08d..cfdff92 100644
--- a/core/modules/menu/lib/Drupal/menu/Access/DeleteMenuAccessCheck.php
+++ b/core/modules/menu/lib/Drupal/menu/Access/DeleteMenuAccessCheck.php
@@ -27,7 +27,7 @@ public function appliesTo() {
   /**
    * {@inheritdoc}
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     if ($account->hasPermission('administer menu') && $menu = $request->attributes->get('menu')) {
       // System-defined menus may not be deleted.
       $system_menus = menu_list_system_menus();
diff --git a/core/modules/node/lib/Drupal/node/Access/NodeRevisionAccessCheck.php b/core/modules/node/lib/Drupal/node/Access/NodeRevisionAccessCheck.php
index 8152e8a..779d71a 100644
--- a/core/modules/node/lib/Drupal/node/Access/NodeRevisionAccessCheck.php
+++ b/core/modules/node/lib/Drupal/node/Access/NodeRevisionAccessCheck.php
@@ -72,7 +72,7 @@ public function applies(Route $route) {
   /**
    * {@inheritdoc}
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     $revision = $this->nodeStorage->loadRevision($request->attributes->get('node_revision'));
     return $this->checkAccess($revision, $account, $route->getRequirement('_access_node_revision')) ? static::ALLOW : static::DENY;
   }
diff --git a/core/modules/overlay/lib/Drupal/overlay/Access/DismissMessageAccessCheck.php b/core/modules/overlay/lib/Drupal/overlay/Access/DismissMessageAccessCheck.php
index 2c35bb8..828d489 100644
--- a/core/modules/overlay/lib/Drupal/overlay/Access/DismissMessageAccessCheck.php
+++ b/core/modules/overlay/lib/Drupal/overlay/Access/DismissMessageAccessCheck.php
@@ -27,7 +27,7 @@ public function applies(Route $route) {
   /**
    * {@inheritdoc}
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     if (!user_access('access overlay', $account)) {
       return static::DENY;
     }
diff --git a/core/modules/rest/lib/Drupal/rest/Access/CSRFAccessCheck.php b/core/modules/rest/lib/Drupal/rest/Access/CSRFAccessCheck.php
index e4ee40e..460de6c 100644
--- a/core/modules/rest/lib/Drupal/rest/Access/CSRFAccessCheck.php
+++ b/core/modules/rest/lib/Drupal/rest/Access/CSRFAccessCheck.php
@@ -43,7 +43,7 @@ public function applies(Route $route) {
   /**
    * Implements AccessCheckInterface::access().
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     $method = $request->getMethod();
     $cookie = $request->cookies->get(session_name(), FALSE);
     // This check only applies if
diff --git a/core/modules/shortcut/lib/Drupal/shortcut/Access/LinkDeleteAccessCheck.php b/core/modules/shortcut/lib/Drupal/shortcut/Access/LinkDeleteAccessCheck.php
index 2f8add9..ab3931e 100644
--- a/core/modules/shortcut/lib/Drupal/shortcut/Access/LinkDeleteAccessCheck.php
+++ b/core/modules/shortcut/lib/Drupal/shortcut/Access/LinkDeleteAccessCheck.php
@@ -27,7 +27,7 @@ public function appliesTo() {
   /**
    * {@inheritdoc}
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     $menu_link = $request->attributes->get('menu_link');
     $set_name = str_replace('shortcut-', '', $menu_link['menu_name']);
     if ($shortcut_set = shortcut_set_load($set_name)) {
diff --git a/core/modules/system/lib/Drupal/system/Access/CronAccessCheck.php b/core/modules/system/lib/Drupal/system/Access/CronAccessCheck.php
index 685377c..d9d7089 100644
--- a/core/modules/system/lib/Drupal/system/Access/CronAccessCheck.php
+++ b/core/modules/system/lib/Drupal/system/Access/CronAccessCheck.php
@@ -27,7 +27,7 @@ public function appliesTo() {
   /**
    * Implements AccessCheckInterface::access().
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     $key = $request->attributes->get('key');
     if ($key != \Drupal::state()->get('system.cron_key')) {
       watchdog('cron', 'Cron could not run because an invalid key was used.', array(), WATCHDOG_NOTICE);
diff --git a/core/modules/system/lib/Drupal/system/Access/SystemPluginUiCheck.php b/core/modules/system/lib/Drupal/system/Access/SystemPluginUiCheck.php
index 22a9822..7d6aef7 100644
--- a/core/modules/system/lib/Drupal/system/Access/SystemPluginUiCheck.php
+++ b/core/modules/system/lib/Drupal/system/Access/SystemPluginUiCheck.php
@@ -45,7 +45,7 @@ public function applies(Route $route) {
   /**
    * {@inheritdoc}
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     if ($request->attributes->get('plugin_id')) {
       // Checks access for a given plugin using the plugin's access() method.
       $plugin_ui = $this->pluginUiManager->createInstance($request->attributes->get('plugin_id'), array());
diff --git a/core/modules/system/tests/modules/router_test/lib/Drupal/router_test/Access/DefinedTestAccessCheck.php b/core/modules/system/tests/modules/router_test/lib/Drupal/router_test/Access/DefinedTestAccessCheck.php
index f3f8efc..a3e1200 100644
--- a/core/modules/system/tests/modules/router_test/lib/Drupal/router_test/Access/DefinedTestAccessCheck.php
+++ b/core/modules/system/tests/modules/router_test/lib/Drupal/router_test/Access/DefinedTestAccessCheck.php
@@ -27,7 +27,7 @@ public function applies(Route $route) {
   /**
    * {@inheritdoc}
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     if ($route->getRequirement('_test_access') === 'TRUE') {
       return static::ALLOW;
     }
diff --git a/core/modules/system/tests/modules/router_test/lib/Drupal/router_test/Access/TestAccessCheck.php b/core/modules/system/tests/modules/router_test/lib/Drupal/router_test/Access/TestAccessCheck.php
index 1a976a6..14245f6 100644
--- a/core/modules/system/tests/modules/router_test/lib/Drupal/router_test/Access/TestAccessCheck.php
+++ b/core/modules/system/tests/modules/router_test/lib/Drupal/router_test/Access/TestAccessCheck.php
@@ -27,7 +27,7 @@ public function applies(Route $route) {
   /**
    * Implements AccessCheckInterface::access().
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     // No opinion, so other access checks should decide if access should be
     // allowed or not.
     return NULL;
diff --git a/core/modules/toolbar/lib/Drupal/toolbar/Access/SubtreeAccess.php b/core/modules/toolbar/lib/Drupal/toolbar/Access/SubtreeAccess.php
index a5139c5..9931175 100644
--- a/core/modules/toolbar/lib/Drupal/toolbar/Access/SubtreeAccess.php
+++ b/core/modules/toolbar/lib/Drupal/toolbar/Access/SubtreeAccess.php
@@ -27,7 +27,7 @@ public function appliesTo() {
   /**
    * {@inheritdoc}
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     $hash = $request->get('hash');
     if ($account->hasPermission('access toolbar') && ($hash == _toolbar_get_subtree_hash())) {
       return TRUE;
diff --git a/core/modules/user/lib/Drupal/user/Access/LoginStatusCheck.php b/core/modules/user/lib/Drupal/user/Access/LoginStatusCheck.php
index 04295ee..da59f07 100644
--- a/core/modules/user/lib/Drupal/user/Access/LoginStatusCheck.php
+++ b/core/modules/user/lib/Drupal/user/Access/LoginStatusCheck.php
@@ -27,7 +27,7 @@ public function appliesTo() {
   /**
    * {@inheritdoc}
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     return $account->isAuthenticated();
   }
 
diff --git a/core/modules/user/lib/Drupal/user/Access/PermissionAccessCheck.php b/core/modules/user/lib/Drupal/user/Access/PermissionAccessCheck.php
index e887b64..d75b5a6 100644
--- a/core/modules/user/lib/Drupal/user/Access/PermissionAccessCheck.php
+++ b/core/modules/user/lib/Drupal/user/Access/PermissionAccessCheck.php
@@ -27,7 +27,7 @@ public function appliesTo() {
   /**
    * Implements AccessCheckInterface::access().
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     $permission = $route->getRequirement('_permission');
     // If the access check fails, return NULL to give other checks a chance.
     return $account->hasPermission($permission) ? static::ALLOW : static::DENY;
diff --git a/core/modules/user/lib/Drupal/user/Access/RegisterAccessCheck.php b/core/modules/user/lib/Drupal/user/Access/RegisterAccessCheck.php
index 342cbbb..7760eff 100644
--- a/core/modules/user/lib/Drupal/user/Access/RegisterAccessCheck.php
+++ b/core/modules/user/lib/Drupal/user/Access/RegisterAccessCheck.php
@@ -27,7 +27,7 @@ public function appliesTo() {
   /**
    * Implements AccessCheckInterface::access().
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     return user_is_anonymous() && (config('user.settings')->get('register') != USER_REGISTER_ADMINISTRATORS_ONLY);
   }
 }
diff --git a/core/modules/user/lib/Drupal/user/Access/RoleAccessCheck.php b/core/modules/user/lib/Drupal/user/Access/RoleAccessCheck.php
index cd5ebf3..20b16f7 100644
--- a/core/modules/user/lib/Drupal/user/Access/RoleAccessCheck.php
+++ b/core/modules/user/lib/Drupal/user/Access/RoleAccessCheck.php
@@ -31,7 +31,7 @@ public function appliesTo() {
   /**
    * {@inheritdoc}
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     // Requirements just allow strings, so this might be a comma separated list.
     $rid_string = $route->getRequirement('_role');
 
diff --git a/core/modules/views/lib/Drupal/views/ViewsAccessCheck.php b/core/modules/views/lib/Drupal/views/ViewsAccessCheck.php
index a709e2e..44c42f7 100644
--- a/core/modules/views/lib/Drupal/views/ViewsAccessCheck.php
+++ b/core/modules/views/lib/Drupal/views/ViewsAccessCheck.php
@@ -29,7 +29,7 @@ public function appliesTo() {
   /**
    * Implements AccessCheckInterface::applies().
    */
-  public function access(AccountInterface $account, Route $route, Request $request) {
+  public function access(Route $route, Request $request, AccountInterface $account = NULL) {
     $access = $account->hasPermission('access all views');
 
     return $access ?: NULL;