diff -u b/core/lib/Drupal/Core/Routing/Access/AccessInterface.php b/core/lib/Drupal/Core/Routing/Access/AccessInterface.php
--- b/core/lib/Drupal/Core/Routing/Access/AccessInterface.php
+++ b/core/lib/Drupal/Core/Routing/Access/AccessInterface.php
@@ -24,10 +24,8 @@
    * @param \Symfony\Component\HttpFoundation\Request $request
    *   The request object.
    *
-   * @return mixed
-   *   TRUE if access is allowed.
-   *   FALSE if not.
-   *   NULL if no opinion.
+   * @return bool|null
+   *   self::ALLOW, self::DENY, or self::KILL.
    */
   public function access(Route $route, Request $request);
 
only in patch2:
unchanged:
--- /dev/null
+++ b/core/lib/Drupal/Core/Access/AccessibleInterface.php
@@ -0,0 +1,31 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Access\AccessibleInterface.
+ */
+
+namespace Drupal\Core\Access;
+
+use Drupal\Core\Session\AccountInterface;
+
+/**
+ * Interface for objects that allow operations to be performed on them.
+ */
+interface AccessibleInterface extends AccessInterface {
+
+  /**
+   * Checks if an operation can be performed.
+   *
+   * @param string $operation
+   *   The operation to be performed.
+   * @param \Drupal\Core\Session\AccountInterface $account
+   *   (optional) The account for which to check access, or NULL to check access
+   *   for the current user. Defaults to NULL.
+   *
+   * @return bool|null
+   *   self::ALLOW, self::DENY, or self::KILL.
+   */
+  public function access($operation, AccountInterface $account = NULL);
+
+}
only in patch2:
unchanged:
--- a/core/lib/Drupal/Core/Entity/EntityAccessControllerInterface.php
+++ b/core/lib/Drupal/Core/Entity/EntityAccessControllerInterface.php
@@ -7,6 +7,7 @@
 
 namespace Drupal\Core\Entity;
 
+use Drupal\Core\Access\AccessInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Language\Language;
 use Drupal\Core\Session\AccountInterface;
@@ -14,7 +15,7 @@
 /**
  * Defines a common interface for entity access controller classes.
  */
-interface EntityAccessControllerInterface {
+interface EntityAccessControllerInterface extends AccessInterface {
 
   /**
    * Checks access to an operation on a given entity or entity translation.
@@ -34,8 +35,8 @@
    *   (optional) The user session for which to check access, or NULL to check
    *   access for the current user. Defaults to NULL.
    *
-   * @return bool
-   *   TRUE if access was granted, FALSE otherwise.
+   * @return bool|null
+   *   self::ALLOW, self::DENY, or self::KILL.
    */
   public function access(EntityInterface $entity, $operation, $langcode = Language::LANGCODE_DEFAULT, AccountInterface $account = NULL);
 
@@ -51,6 +52,9 @@ public function access(EntityInterface $entity, $operation, $langcode = Language
    * @param array $context
    *   (optional) An array of key-value pairs to pass additional context when
    *   needed.
+   *
+   * return bool|null
+   *   self::ALLOW, self::DENY, or self::KILL.
    */
   public function createAccess($entity_bundle = NULL, AccountInterface $account = NULL, array $context = array());
 
only in patch2:
unchanged:
--- a/core/lib/Drupal/Core/Entity/EntityInterface.php
+++ b/core/lib/Drupal/Core/Entity/EntityInterface.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\Core\Entity;
 
-use Drupal\Core\TypedData\AccessibleInterface;
+use Drupal\Core\Access\AccessibleInterface;
 use Drupal\Core\TypedData\ComplexDataInterface;
 use Drupal\Core\TypedData\IdentifiableInterface;
 use Drupal\Core\TypedData\TranslatableInterface;
only in patch2:
unchanged:
--- a/core/lib/Drupal/Core/Entity/Field/FieldInterface.php
+++ b/core/lib/Drupal/Core/Entity/Field/FieldInterface.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\Core\Entity\Field;
 
-use Drupal\Core\TypedData\AccessibleInterface;
+use Drupal\Core\Access\AccessibleInterface;
 use Drupal\Core\TypedData\ListInterface;
 
 /**
only in patch2:
unchanged:
--- a/core/lib/Drupal/Core/TypedData/AccessibleInterface.php
+++ /dev/null
@@ -1,39 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains \Drupal\Core\TypedData\AccessibleInterface.
- */
-
-namespace Drupal\Core\TypedData;
-
-use Drupal\Core\Session\AccountInterface;
-
-/**
- * Interface for checking access.
- */
-interface AccessibleInterface {
-
-  /**
-   * Checks data value access.
-   *
-   * @param string $operation
-   *   (optional) The operation to be performed. Supported values are:
-   *   - view
-   *   - create
-   *   - update
-   *   - delete
-   *   Defaults to 'view'.
-   * @param Drupal\Core\Session\AccountInterface $account
-   *   (optional) The user for which to check access, or NULL to check access
-   *   for the current user. Defaults to NULL.
-   *
-   * @return bool
-   *   TRUE if the given user has access for the given operation, FALSE
-   *   otherwise.
-   *
-   * @todo Don't depend on module level code.
-   */
-  public function access($operation = 'view', AccountInterface $account = NULL);
-
-}
only in patch2:
unchanged:
--- a/core/modules/node/lib/Drupal/node/Plugin/Search/NodeSearch.php
+++ b/core/modules/node/lib/Drupal/node/Plugin/Search/NodeSearch.php
@@ -17,7 +17,7 @@
 use Drupal\Core\KeyValueStore\KeyValueStoreInterface;
 use Drupal\Core\Language\Language;
 use Drupal\Core\Session\AccountInterface;
-use Drupal\Core\TypedData\AccessibleInterface;
+use Drupal\Core\Access\AccessibleInterface;
 use Drupal\Core\Database\Query\Condition;
 use Drupal\search\Annotation\SearchPlugin;
 use Drupal\search\Plugin\SearchPluginBase;
only in patch2:
unchanged:
--- a/core/modules/search/lib/Drupal/search/SearchPluginManager.php
+++ b/core/modules/search/lib/Drupal/search/SearchPluginManager.php
@@ -111,7 +111,7 @@ public function pluginAccess($plugin_id, AccountInterface $account) {
       return FALSE;
     }
     // Plugins that implement AccessibleInterface can deny access.
-    if (is_subclass_of($definition['class'], '\Drupal\Core\TypedData\AccessibleInterface')) {
+    if (is_subclass_of($definition['class'], '\Drupal\Core\Access\AccessibleInterface')) {
       return $this->createInstance($plugin_id)->access('view', $account);
     }
     return TRUE;
only in patch2:
unchanged:
--- a/core/modules/system/lib/Drupal/system/Tests/Entity/EntityAccessTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Entity/EntityAccessTest.php
@@ -9,7 +9,7 @@
 
 use Drupal\Core\Language\Language;
 use Drupal\Core\Session\AccountInterface;
-use Drupal\Core\TypedData\AccessibleInterface;
+use Drupal\Core\Access\AccessibleInterface;
 use Drupal\Core\Entity\EntityAccessController;
 
 /**
only in patch2:
unchanged:
--- a/core/modules/user/lib/Drupal/user/Plugin/Search/UserSearch.php
+++ b/core/modules/user/lib/Drupal/user/Plugin/Search/UserSearch.php
@@ -12,7 +12,7 @@
 use Drupal\Core\Entity\EntityManager;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Session\AccountInterface;
-use Drupal\Core\TypedData\AccessibleInterface;
+use Drupal\Core\Access\AccessibleInterface;
 use Drupal\search\Annotation\SearchPlugin;
 use Drupal\search\Plugin\SearchPluginBase;
 use Symfony\Component\DependencyInjection\ContainerInterface;