diff --git a/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php b/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php
index d23341b..9ba0de1 100644
--- a/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php
+++ b/core/lib/Drupal/Core/Config/Entity/ConfigEntityStorage.php
@@ -183,7 +183,7 @@ protected function doLoadMultiple(array $ids = NULL) {
    */
   protected function doCreate(array $values) {
     // Set default language to site default if not provided.
-    $values += array('langcode' => $this->languageManager->getDefaultLanguage()->id);
+    $values += array($this->langcodeKey => $this->languageManager->getDefaultLanguage()->id);
     $entity = new $this->entityClass($values, $this->entityTypeId);
 
     // Default status to enabled.
diff --git a/core/lib/Drupal/Core/Config/Entity/ConfigEntityType.php b/core/lib/Drupal/Core/Config/Entity/ConfigEntityType.php
index 7960edc..6e87523 100644
--- a/core/lib/Drupal/Core/Config/Entity/ConfigEntityType.php
+++ b/core/lib/Drupal/Core/Config/Entity/ConfigEntityType.php
@@ -98,8 +98,11 @@ public function getConfigPrefix() {
    * {@inheritdoc}
    */
   public function getKeys() {
-    // Always add a default 'uuid' key.
-    return array('uuid' => 'uuid') + parent::getKeys();
+    // Always add default 'uuid' and 'langcode' keys.
+    return array(
+      'uuid' => 'uuid',
+      'langcode' => 'langcode',
+    ) + parent::getKeys();
   }
 
 
diff --git a/core/lib/Drupal/Core/Entity/ContentEntityBase.php b/core/lib/Drupal/Core/Entity/ContentEntityBase.php
index 1895cfd..93e23a3 100644
--- a/core/lib/Drupal/Core/Entity/ContentEntityBase.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityBase.php
@@ -73,6 +73,13 @@
   protected $languages;
 
   /**
+   * The language entity key.
+   *
+   * @var string
+   */
+  protected $langcodeKey;
+
+  /**
    * Language code identifying the entity active language.
    *
    * This is the language field accessors will use to determine which field
@@ -142,6 +149,7 @@ public function __construct(array $values, $entity_type, $bundle = FALSE, $trans
     $this->entityTypeId = $entity_type;
     $this->entityKeys['bundle'] = $bundle ? $bundle : $this->entityTypeId;
     $this->languages = $this->languageManager()->getLanguages(Language::STATE_ALL);
+    $this->langcodeKey = $this->getEntityType()->getKey('langcode');
 
     foreach ($values as $key => $value) {
       // If the key matches an existing property set the value to the property
@@ -462,8 +470,8 @@ protected function getTranslatedField($name, $langcode) {
    * {@inheritdoc}
    */
   public function set($name, $value, $notify = TRUE) {
-    // If default language or an entity key changes we need to react to that.
-    $notify = $name == 'langcode' || in_array($name, $this->getEntityType()->getKeys());
+    // If an entity key changes we need to react to that.
+    $notify = in_array($name, $this->getEntityType()->getKeys());
     $this->get($name)->setValue($value, $notify);
   }
 
@@ -571,7 +579,12 @@ public function language() {
    */
   protected function setDefaultLangcode() {
     // Get the language code if the property exists.
-    if ($this->hasField('langcode') && ($item = $this->get('langcode')) && isset($item->language)) {
+    // Try to read the value directly from the list of entity keys which got
+    // initialized in __construct(). This avoids creating a field item object.
+    if (isset($this->entityKeys['langcode'])) {
+      $this->defaultLangcode = $this->entityKeys['langcode'];
+    }
+    elseif ($this->hasField($this->langcodeKey) && ($item = $this->get($this->langcodeKey)) && isset($item->language)) {
       $this->defaultLangcode = $item->language->id;
     }
     if (empty($this->defaultLangcode)) {
@@ -580,8 +593,8 @@ protected function setDefaultLangcode() {
     }
     // This needs to be initialized manually as it is skipped when instantiating
     // the language field object to avoid infinite recursion.
-    if (!empty($this->fields['langcode'])) {
-      $this->fields['langcode'][Language::LANGCODE_DEFAULT]->setLangcode($this->defaultLangcode);
+    if (!empty($this->fields[$this->langcodeKey])) {
+      $this->fields[$this->langcodeKey][Language::LANGCODE_DEFAULT]->setLangcode($this->defaultLangcode);
     }
   }
 
@@ -603,7 +616,7 @@ protected function updateFieldLangcodes($langcode) {
    * {@inheritdoc}
    */
   public function onChange($name) {
-    if ($name == 'langcode') {
+    if ($name == $this->langcodeKey) {
       $this->setDefaultLangcode();
       if (isset($this->translations[$this->defaultLangcode])) {
         $message = String::format('A translation already exists for the specified language (@langcode).', array('@langcode' => $this->defaultLangcode));
@@ -738,7 +751,11 @@ public function addTranslation($langcode, array $values = array()) {
     // Instantiate a new empty entity so default values will be populated in the
     // specified language.
     $entity_type = $this->getEntityType();
-    $default_values = array($entity_type->getKey('bundle') => $this->bundle(), 'langcode' => $langcode);
+
+    $default_values = array(
+      $entity_type->getKey('bundle') => $this->bundle(),
+      $this->langcodeKey => $langcode,
+    );
     $entity = $this->entityManager()
       ->getStorage($this->getEntityTypeId())
       ->create($default_values);
diff --git a/core/lib/Drupal/Core/Entity/ContentEntityDatabaseStorage.php b/core/lib/Drupal/Core/Entity/ContentEntityDatabaseStorage.php
index 2214894..cef562c 100644
--- a/core/lib/Drupal/Core/Entity/ContentEntityDatabaseStorage.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityDatabaseStorage.php
@@ -51,6 +51,15 @@ class ContentEntityDatabaseStorage extends ContentEntityStorageBase {
   protected $dataTable;
 
   /**
+   * Name of entity's default language database table field.
+   *
+   * Is only set if the entity has multilingual support.
+   *
+   * @var string
+   */
+  protected $defaultLangcodeKey;
+
+  /**
    * The table that stores revision field data if the entity supports revisions.
    *
    * @var string
@@ -109,6 +118,9 @@ public function __construct(EntityTypeInterface $entity_type, Connection $databa
     // Check if the entity type has a dedicated table for fields.
     if ($data_table = $this->entityType->getDataTable()) {
       $this->dataTable = $data_table;
+      // Instead of hardcoding this value throughout this class, we store it in
+      // a member variable to allow subclasses to override this.
+      $this->defaultLangcodeKey = 'default_langcode';
       // Entity types having both revision and translation support should always
       // define a revision data table.
       if ($this->revisionTable && $revision_data_table = $this->entityType->getRevisionDataTable()) {
@@ -229,7 +241,7 @@ protected function attachPropertyData(array &$entities) {
 
         // Field values in default language are stored with
         // Language::LANGCODE_DEFAULT as key.
-        $langcode = empty($values['default_langcode']) ? $values['langcode'] : Language::LANGCODE_DEFAULT;
+        $langcode = empty($values[$this->defaultLangcodeKey]) ? $values[$this->langcodeKey] : Language::LANGCODE_DEFAULT;
         $translations[$id][$langcode] = TRUE;
 
         foreach (array_keys($field_definitions) as $field_name) {
@@ -306,13 +318,13 @@ protected function buildPropertyQuery(QueryInterface $entity_query, array $value
       //   apply to the default language. See http://drupal.org/node/1866330.
       // Default to the original entity language if not explicitly specified
       // otherwise.
-      if (!array_key_exists('default_langcode', $values)) {
-        $values['default_langcode'] = 1;
+      if (!array_key_exists($this->defaultLangcodeKey, $values)) {
+        $values[$this->defaultLangcodeKey] = 1;
       }
       // If the 'default_langcode' flag is explicitly not set, we do not care
       // whether the queried values are in the original entity language or not.
-      elseif ($values['default_langcode'] === NULL) {
-        unset($values['default_langcode']);
+      elseif ($values[$this->defaultLangcodeKey] === NULL) {
+        unset($values[$this->defaultLangcodeKey]);
       }
     }
 
diff --git a/core/lib/Drupal/Core/Entity/Entity.php b/core/lib/Drupal/Core/Entity/Entity.php
index 557ddf3..a1ace19 100644
--- a/core/lib/Drupal/Core/Entity/Entity.php
+++ b/core/lib/Drupal/Core/Entity/Entity.php
@@ -290,7 +290,8 @@ public function access($operation, AccountInterface $account = NULL) {
    * {@inheritdoc}
    */
   public function language() {
-    $language = $this->languageManager()->getLanguage($this->langcode);
+    $langcode = $this->{$this->getEntityType()->getKey('langcode')};
+    $language = $this->languageManager()->getLanguage($langcode);
     if (!$language) {
       // Make sure we return a proper language object.
       $language = new Language(array('id' => Language::LANGCODE_NOT_SPECIFIED));
diff --git a/core/lib/Drupal/Core/Entity/EntityManager.php b/core/lib/Drupal/Core/Entity/EntityManager.php
index c4a901c..0be8fd3 100644
--- a/core/lib/Drupal/Core/Entity/EntityManager.php
+++ b/core/lib/Drupal/Core/Entity/EntityManager.php
@@ -399,7 +399,7 @@ protected function buildBaseFieldDefinitions($entity_type_id) {
 
     // Ensure defined entity keys are there and have proper revisionable and
     // translatable values.
-    $keys = array_filter($entity_type->getKeys() + array('langcode' => 'langcode'));
+    $keys = array_filter($entity_type->getKeys());
     foreach ($keys as $key => $field_name) {
       if (isset($base_field_definitions[$field_name]) && in_array($key, array('id', 'revision', 'uuid', 'bundle')) && $base_field_definitions[$field_name]->isRevisionable()) {
         throw new \LogicException(String::format('The @field field cannot be revisionable as it is used as @key entity key.', array('@field' => $base_field_definitions[$field_name]->getLabel(), '@key' => $key)));
diff --git a/core/lib/Drupal/Core/Entity/EntityStorageBase.php b/core/lib/Drupal/Core/Entity/EntityStorageBase.php
index 5d24441..473d0c6 100644
--- a/core/lib/Drupal/Core/Entity/EntityStorageBase.php
+++ b/core/lib/Drupal/Core/Entity/EntityStorageBase.php
@@ -53,6 +53,13 @@
   protected $uuidKey;
 
   /**
+   * The name of the entity langcode property.
+   *
+   * @var string
+   */
+  protected $langcodeKey;
+
+  /**
    * The UUID service.
    *
    * @var \Drupal\Component\Uuid\UuidInterface
@@ -76,6 +83,7 @@ public function __construct(EntityTypeInterface $entity_type) {
     $this->entityTypeId = $entity_type->id();
     $this->entityType = $entity_type;
     $this->idKey = $this->entityType->getKey('id');
+    $this->langcodeKey = $this->entityType->getKey('langcode');
     $this->entityClass = $this->entityType->getClass();
   }
 
diff --git a/core/lib/Drupal/Core/Entity/EntityType.php b/core/lib/Drupal/Core/Entity/EntityType.php
index 4382665..7d03e9b 100644
--- a/core/lib/Drupal/Core/Entity/EntityType.php
+++ b/core/lib/Drupal/Core/Entity/EntityType.php
@@ -257,7 +257,11 @@ public function isFieldDataCacheable() {
    * {@inheritdoc}
    */
   public function getKeys() {
-    return $this->entity_keys + array('revision' => '', 'bundle' => '');
+    return $this->entity_keys + array(
+      'revision' => '',
+      'bundle' => '',
+      'langcode' => '',
+    );
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Entity/EntityTypeInterface.php b/core/lib/Drupal/Core/Entity/EntityTypeInterface.php
index a6e39aa..30532d3 100644
--- a/core/lib/Drupal/Core/Entity/EntityTypeInterface.php
+++ b/core/lib/Drupal/Core/Entity/EntityTypeInterface.php
@@ -83,24 +83,27 @@ public function getClass();
    *   - id: The name of the property that contains the primary ID of the
    *     entity. Every entity object passed to the Field API must have this
    *     property and its value must be numeric.
+   *   - uuid: (optional) The name of the property that contains the universally
+   *     unique identifier of the entity, which is used to distinctly identify
+   *     an entity across different systems.
    *   - revision: (optional) The name of the property that contains the
    *     revision ID of the entity. The Field API assumes that all revision IDs
    *     are unique across all entities of a type. If this entry is omitted
    *     the entities of this type are not revisionable.
+   *   - langcode: (optional) The name of the property that contains the
+   *     language code. For instance, if the entity's language is located in
+   *     $entity->language, then 'language' should be specified here.
    *   - bundle: (optional) The name of the property that contains the bundle
    *     name for the entity. The bundle name defines which set of fields are
    *     attached to the entity (e.g. what nodes call "content type"). This
    *     entry can be omitted if this entity type exposes a single bundle (such
    *     that all entities have the same collection of fields). The name of this
    *     single bundle will be the same as the entity type.
-   *   - label: The name of the property that contains the entity label. For
-   *     example, if the entity's label is located in $entity->subject, then
-   *     'subject' should be specified here. If complex logic is required to
-   *     build the label, a 'label_callback' should be defined instead (see the
-   *     $label_callback block above for details).
-   *   - uuid (optional): The name of the property that contains the universally
-   *     unique identifier of the entity, which is used to distinctly identify
-   *     an entity across different systems.
+   *   - label: (optional) The name of the property that contains the entity
+   *     label. For example, if the entity's label is located in
+   *     $entity->subject, then 'subject' should be specified here. If complex
+   *     logic is required to build the label, a 'label_callback' should be
+   *     defined instead (see the $label_callback block above for details).
    */
   public function getKeys();
 
diff --git a/core/modules/aggregator/src/Entity/Feed.php b/core/modules/aggregator/src/Entity/Feed.php
index 24430b9..84697c3 100644
--- a/core/modules/aggregator/src/Entity/Feed.php
+++ b/core/modules/aggregator/src/Entity/Feed.php
@@ -10,6 +10,7 @@
 use Drupal\Core\Entity\ContentEntityBase;
 use Drupal\Core\Entity\EntityTypeInterface;
 use Drupal\Core\Field\FieldDefinition;
+use Drupal\Core\Language\Language;
 use Symfony\Component\DependencyInjection\Container;
 use Drupal\Core\Entity\EntityStorageInterface;
 use Drupal\aggregator\FeedInterface;
@@ -38,8 +39,9 @@
  *   fieldable = TRUE,
  *   entity_keys = {
  *     "id" = "fid",
- *     "label" = "title",
  *     "uuid" = "uuid",
+ *     "langcode" = "langcode",
+ *     "label" = "title",
  *   }
  * )
  */
diff --git a/core/modules/aggregator/src/Entity/Item.php b/core/modules/aggregator/src/Entity/Item.php
index bb9e0aa..fda3ff7 100644
--- a/core/modules/aggregator/src/Entity/Item.php
+++ b/core/modules/aggregator/src/Entity/Item.php
@@ -27,6 +27,7 @@
  *   fieldable = TRUE,
  *   entity_keys = {
  *     "id" = "iid",
+ *     "langcode" = "langcode",
  *     "label" = "title",
  *   }
  * )
diff --git a/core/modules/block/custom_block/src/Entity/CustomBlock.php b/core/modules/block/custom_block/src/Entity/CustomBlock.php
index 71913b7..dcf5c4e 100644
--- a/core/modules/block/custom_block/src/Entity/CustomBlock.php
+++ b/core/modules/block/custom_block/src/Entity/CustomBlock.php
@@ -45,10 +45,11 @@
  *   translatable = TRUE,
  *   entity_keys = {
  *     "id" = "id",
+ *     "uuid" = "uuid",
  *     "revision" = "revision_id",
+ *     "langcode" = "langcode",
  *     "bundle" = "type",
  *     "label" = "info",
- *     "uuid" = "uuid"
  *   },
  *   bundle_entity_type = "custom_block_type"
  * )
diff --git a/core/modules/comment/src/Entity/Comment.php b/core/modules/comment/src/Entity/Comment.php
index de10346..2bfe59c 100644
--- a/core/modules/comment/src/Entity/Comment.php
+++ b/core/modules/comment/src/Entity/Comment.php
@@ -40,9 +40,10 @@
  *   translatable = TRUE,
  *   entity_keys = {
  *     "id" = "cid",
+ *     "uuid" = "uuid",
+ *     "langcode" = "langcode",
  *     "bundle" = "field_id",
  *     "label" = "subject",
- *     "uuid" = "uuid"
  *   },
  *   links = {
  *     "canonical" = "comment.permalink",
diff --git a/core/modules/contact/src/Entity/Message.php b/core/modules/contact/src/Entity/Message.php
index f2c05fc..7c47315 100644
--- a/core/modules/contact/src/Entity/Message.php
+++ b/core/modules/contact/src/Entity/Message.php
@@ -26,7 +26,7 @@
  *     }
  *   },
  *   entity_keys = {
- *     "bundle" = "category"
+ *     "bundle" = "category",
  *   },
  *   bundle_entity_type = "contact_category",
  *   fieldable = TRUE,
diff --git a/core/modules/content_translation/content_translation.module b/core/modules/content_translation/content_translation.module
index 4e29f4c..6eb3c33 100644
--- a/core/modules/content_translation/content_translation.module
+++ b/core/modules/content_translation/content_translation.module
@@ -248,8 +248,19 @@ function _content_translation_menu_strip_loaders($path) {
  *   The entity whose translation overview should be displayed.
  */
 function content_translation_translate_access(EntityInterface $entity) {
-  return $entity instanceof ContentEntityInterface && empty($entity->getUntranslated()->language()->locked) && \Drupal::languageManager()->isMultilingual() && $entity->isTranslatable() &&
-    (user_access('create content translations') || user_access('update content translations') || user_access('delete content translations'));
+  $account = \Drupal::currentUser();
+
+  $access = $entity instanceof ContentEntityInterface;
+  $access = $access && empty($entity->getUntranslated()->language()->locked);
+  $access = $access && \Drupal::languageManager()->isMultilingual();
+  $access = $access && $entity->isTranslatable();
+  $access = $access && (
+    $account->hasPermission('create content translations') ||
+    $account->hasPermission('update content translations') ||
+    $account->hasPermission('delete content translations')
+  );
+
+  return $access;
 }
 
 /**
diff --git a/core/modules/file/src/Entity/File.php b/core/modules/file/src/Entity/File.php
index 39f27d6..848400b 100644
--- a/core/modules/file/src/Entity/File.php
+++ b/core/modules/file/src/Entity/File.php
@@ -28,25 +28,15 @@
  *   base_table = "file_managed",
  *   entity_keys = {
  *     "id" = "fid",
+ *     "uuid" = "uuid",
+ *     "langcode" = "langcode",
  *     "label" = "filename",
- *     "uuid" = "uuid"
  *   }
  * )
  */
 class File extends ContentEntityBase implements FileInterface {
 
   /**
-   * The plain data values of the contained properties.
-   *
-   * Define default values.
-   *
-   * @var array
-   */
-  protected $values = array(
-    'langcode' => array(Language::LANGCODE_DEFAULT => array(0 => array('value' => Language::LANGCODE_NOT_SPECIFIED))),
-  );
-
-  /**
    * {@inheritdoc}
    */
   public function getFilename() {
diff --git a/core/modules/menu_link/src/Entity/MenuLink.php b/core/modules/menu_link/src/Entity/MenuLink.php
index d446643..52aa55a 100644
--- a/core/modules/menu_link/src/Entity/MenuLink.php
+++ b/core/modules/menu_link/src/Entity/MenuLink.php
@@ -38,7 +38,8 @@
  *     "id" = "mlid",
  *     "label" = "link_title",
  *     "uuid" = "uuid",
- *     "bundle" = "bundle"
+ *     "bundle" = "bundle",
+ *     "langcode" = "langcode",
  *   },
  * )
  */
diff --git a/core/modules/node/src/Entity/Node.php b/core/modules/node/src/Entity/Node.php
index 1d21504..359792e 100644
--- a/core/modules/node/src/Entity/Node.php
+++ b/core/modules/node/src/Entity/Node.php
@@ -44,10 +44,11 @@
  *   translatable = TRUE,
  *   entity_keys = {
  *     "id" = "nid",
+ *     "uuid" = "uuid",
  *     "revision" = "vid",
+ *     "langcode" = "langcode",
  *     "bundle" = "type",
  *     "label" = "title",
- *     "uuid" = "uuid"
  *   },
  *   bundle_entity_type = "node_type",
  *   permission_granularity = "bundle",
diff --git a/core/modules/shortcut/src/Entity/Shortcut.php b/core/modules/shortcut/src/Entity/Shortcut.php
index 03be8c8..8974a27 100644
--- a/core/modules/shortcut/src/Entity/Shortcut.php
+++ b/core/modules/shortcut/src/Entity/Shortcut.php
@@ -37,8 +37,9 @@
  *   entity_keys = {
  *     "id" = "id",
  *     "uuid" = "uuid",
+ *     "langcode" = "langcode",
  *     "bundle" = "shortcut_set",
- *     "label" = "title"
+ *     "label" = "title",
  *   },
  *   links = {
  *     "canonical" = "shortcut.link_edit",
diff --git a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTest.php b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTest.php
index 01e6872..35e73db 100644
--- a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTest.php
+++ b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTest.php
@@ -37,7 +37,8 @@
  *     "id" = "id",
  *     "uuid" = "uuid",
  *     "bundle" = "type",
- *     "label" = "name"
+ *     "langcode" = "langcode",
+ *     "label" = "name",
  *   },
  *   links = {
  *     "canonical" = "entity_test.render",
diff --git a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestBaseFieldDisplay.php b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestBaseFieldDisplay.php
index 6a8badd..b719cb2 100644
--- a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestBaseFieldDisplay.php
+++ b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestBaseFieldDisplay.php
@@ -29,7 +29,7 @@
  *     "id" = "id",
  *     "uuid" = "uuid",
  *     "revision" = "revision_id",
- *     "bundle" = "type"
+ *     "bundle" = "type",
  *   },
  *   links = {
  *     "edit-form" = "entity_test.edit_entity_test",
diff --git a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestCache.php b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestCache.php
index 07d0e75..2090e5a 100644
--- a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestCache.php
+++ b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestCache.php
@@ -26,7 +26,7 @@
  *   entity_keys = {
  *     "id" = "id",
  *     "uuid" = "uuid",
- *     "bundle" = "type"
+ *     "bundle" = "type",
  *   }
  * )
  */
diff --git a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestLabel.php b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestLabel.php
index 90a56a5..00fe8d0 100644
--- a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestLabel.php
+++ b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestLabel.php
@@ -21,7 +21,7 @@
  *   entity_keys = {
  *     "id" = "id",
  *     "label" = "name",
- *     "bundle" = "type"
+ *     "bundle" = "type",
  *   }
  * )
  */
diff --git a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestLabelCallback.php b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestLabelCallback.php
index 481711f..0088d70 100644
--- a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestLabelCallback.php
+++ b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestLabelCallback.php
@@ -20,7 +20,7 @@
  *   fieldable = TRUE,
  *   entity_keys = {
  *     "id" = "id",
- *     "bundle" = "type"
+ *     "bundle" = "type",
  *   }
  * )
  */
diff --git a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestMul.php b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestMul.php
index 9930262..c934f4c 100644
--- a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestMul.php
+++ b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestMul.php
@@ -33,8 +33,9 @@
  *   entity_keys = {
  *     "id" = "id",
  *     "uuid" = "uuid",
+ *     "langcode" = "langcode",
  *     "bundle" = "type",
- *     "label" = "name"
+ *     "label" = "name",
  *   },
  *   links = {
  *     "canonical" = "entity_test.edit_entity_test_mul",
diff --git a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestMulRev.php b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestMulRev.php
index 21f6c54..33cf2b7 100644
--- a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestMulRev.php
+++ b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestMulRev.php
@@ -35,7 +35,8 @@
  *     "id" = "id",
  *     "uuid" = "uuid",
  *     "revision" = "revision_id",
- *     "bundle" = "type"
+ *     "langcode" = "langcode",
+ *     "bundle" = "type",
  *   },
  *   links = {
  *     "canonical" = "entity_test.edit_entity_test_mulrev",
diff --git a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestNoLabel.php b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestNoLabel.php
index 6dc35d4..4ca0b89 100644
--- a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestNoLabel.php
+++ b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestNoLabel.php
@@ -17,7 +17,7 @@
  *   base_table = "entity_test",
  *   entity_keys = {
  *     "id" = "id",
- *     "bundle" = "type"
+ *     "bundle" = "type",
  *   }
  * )
  */
diff --git a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestRev.php b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestRev.php
index ea99ed0..1f58d81 100644
--- a/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestRev.php
+++ b/core/modules/system/tests/modules/entity_test/src/Entity/EntityTestRev.php
@@ -32,6 +32,7 @@
  *     "id" = "id",
  *     "uuid" = "uuid",
  *     "revision" = "revision_id",
+ *     "langcode" = "langcode",
  *     "bundle" = "type",
  *     "label" = "name",
  *   },
diff --git a/core/modules/taxonomy/src/Entity/Term.php b/core/modules/taxonomy/src/Entity/Term.php
index 510524a..5c32848 100644
--- a/core/modules/taxonomy/src/Entity/Term.php
+++ b/core/modules/taxonomy/src/Entity/Term.php
@@ -38,9 +38,10 @@
  *   translatable = TRUE,
  *   entity_keys = {
  *     "id" = "tid",
+ *     "uuid" = "uuid",
+ *     "langcode" = "langcode",
  *     "bundle" = "vid",
  *     "label" = "name",
- *     "uuid" = "uuid"
  *   },
  *   bundle_entity_type = "taxonomy_vocabulary",
  *   links = {
diff --git a/core/modules/user/src/Entity/User.php b/core/modules/user/src/Entity/User.php
index 25eb641..b321c0c 100644
--- a/core/modules/user/src/Entity/User.php
+++ b/core/modules/user/src/Entity/User.php
@@ -41,7 +41,8 @@
  *   translatable = TRUE,
  *   entity_keys = {
  *     "id" = "uid",
- *     "uuid" = "uuid"
+ *     "uuid" = "uuid",
+ *     "langcode" = "langcode",
  *   },
  *   links = {
  *     "canonical" = "user.view",
diff --git a/core/tests/Drupal/Tests/Core/Config/Entity/ConfigEntityStorageTest.php b/core/tests/Drupal/Tests/Core/Config/Entity/ConfigEntityStorageTest.php
index 37019f5..304c7ca 100644
--- a/core/tests/Drupal/Tests/Core/Config/Entity/ConfigEntityStorageTest.php
+++ b/core/tests/Drupal/Tests/Core/Config/Entity/ConfigEntityStorageTest.php
@@ -123,6 +123,7 @@ protected function setUp() {
       ->will($this->returnValueMap(array(
         array('id', 'id'),
         array('uuid', 'uuid'),
+        array('langcode', 'langcode'),
       )));
     $this->entityType->expects($this->any())
       ->method('id')
diff --git a/core/tests/Drupal/Tests/Core/Entity/EntityManagerTest.php b/core/tests/Drupal/Tests/Core/Entity/EntityManagerTest.php
index e5eeda0..0cda54e 100644
--- a/core/tests/Drupal/Tests/Core/Entity/EntityManagerTest.php
+++ b/core/tests/Drupal/Tests/Core/Entity/EntityManagerTest.php
@@ -682,7 +682,7 @@ public function testGetFieldStorageDefinitionsWithCaching() {
    * @expectedException \LogicException
    */
   public function testGetBaseFieldDefinitionsInvalidDefinition() {
-    $langcode_definition = $this->setUpEntityWithFieldDefinition(FALSE, 'langcode');
+    $langcode_definition = $this->setUpEntityWithFieldDefinition(FALSE, 'langcode', 1, array('langcode' => 'langcode'));
     $langcode_definition->expects($this->once())
       ->method('isTranslatable')
       ->will($this->returnValue(TRUE));
@@ -734,11 +734,17 @@ public function testGetFieldDefinitionsProvider() {
    *   ModuleHandlerInterface::invokeAll() implementation. Defaults to FALSE.
    * @param string $field_definition_id
    *   (optional) The ID to use for the field definition. Defaults to 'id'.
+   * @param int $base_field_definition_calls
+   *   (optional) The number of times EntityInterface::baseFieldDefinitions() is
+   *   expected to be called. Defaults to 1.
+   * @param array $entity_keys
+   *   (optional) An array of entity keys for the mocked entity type. Defaults
+   *   to an empty array.
    *
    * @return \Drupal\Core\Field\FieldDefinition|\PHPUnit_Framework_MockObject_MockObject
    *   A field definition object.
    */
-  protected function setUpEntityWithFieldDefinition($custom_invoke_all = FALSE, $field_definition_id = 'id', $base_field_definition_calls = 1) {
+  protected function setUpEntityWithFieldDefinition($custom_invoke_all = FALSE, $field_definition_id = 'id', $base_field_definition_calls = 1, $entity_keys = array()) {
     $entity_type = $this->getMock('Drupal\Core\Entity\EntityTypeInterface');
     $entity = $this->getMock('Drupal\Tests\Core\Entity\TestContentEntityInterface');
     $entity_class = get_class($entity);
@@ -748,7 +754,7 @@ protected function setUpEntityWithFieldDefinition($custom_invoke_all = FALSE, $f
       ->will($this->returnValue($entity_class));
     $entity_type->expects($this->any())
       ->method('getKeys')
-      ->will($this->returnValue(array()));
+      ->will($this->returnValue($entity_keys));
     $entity_type->expects($this->any())
       ->method('isSubclassOf')
       ->with($this->equalTo('\Drupal\Core\Entity\ContentEntityInterface'))
diff --git a/core/tests/Drupal/Tests/Core/Entity/EntityTypeTest.php b/core/tests/Drupal/Tests/Core/Entity/EntityTypeTest.php
index ac29654..bf34308 100644
--- a/core/tests/Drupal/Tests/Core/Entity/EntityTypeTest.php
+++ b/core/tests/Drupal/Tests/Core/Entity/EntityTypeTest.php
@@ -82,9 +82,9 @@ public function testHasKey($entity_keys, $expected) {
    */
   public function providerTestGetKeys() {
     return array(
-      array(array(), array('revision' => '', 'bundle' => '')),
-      array(array('id' => 'id'), array('id' => 'id', 'revision' => '', 'bundle' => '')),
-      array(array('bundle' => 'bundle'), array('bundle' => 'bundle', 'revision' => '')),
+      array(array(), array('revision' => '', 'bundle' => '', 'langcode' => '')),
+      array(array('id' => 'id'), array('id' => 'id', 'revision' => '', 'bundle' => '', 'langcode' => '')),
+      array(array('bundle' => 'bundle'), array('bundle' => 'bundle', 'revision' => '', 'langcode' => '')),
     );
   }
 
diff --git a/core/tests/Drupal/Tests/Core/Entity/EntityUnitTest.php b/core/tests/Drupal/Tests/Core/Entity/EntityUnitTest.php
index 3ecc8de..635c617 100644
--- a/core/tests/Drupal/Tests/Core/Entity/EntityUnitTest.php
+++ b/core/tests/Drupal/Tests/Core/Entity/EntityUnitTest.php
@@ -239,6 +239,11 @@ public function testAccess() {
    * @covers ::language
    */
   public function testLanguage() {
+    $this->entityType->expects($this->any())
+      ->method('getKey')
+      ->will($this->returnValueMap(array(
+        array('langcode', 'langcode'),
+      )));
     $this->assertSame('en', $this->entity->language()->id);
   }