diff --git a/core/modules/system/language.api.php b/core/modules/system/language.api.php
index ed6de6c..1fb40e2 100644
--- a/core/modules/system/language.api.php
+++ b/core/modules/system/language.api.php
@@ -5,6 +5,8 @@
  * Hooks provided by the base system for language support.
  */
 
+use Drupal\Core\Language\LanguageInterface;
+
 /**
  * @addtogroup hooks
  * @{
@@ -27,7 +29,7 @@
 function hook_language_switch_links_alter(array &$links, $type, $path) {
   $language_interface = \Drupal::languageManager()->getCurrentLanguage();
 
-  if ($type == \Drupal\Core\Language\Language::TYPE_CONTENT && isset($links[$language_interface->id])) {
+  if ($type == LanguageInterface::TYPE_CONTENT && isset($links[$language_interface->id])) {
     foreach ($links[$language_interface->id] as $link) {
       $link['attributes']['class'][] = 'active-language';
     }
diff --git a/core/modules/text/src/Tests/Formatter/TextPlainUnitTest.php b/core/modules/text/src/Tests/Formatter/TextPlainUnitTest.php
index 1c35b24..8725b8a 100644
--- a/core/modules/text/src/Tests/Formatter/TextPlainUnitTest.php
+++ b/core/modules/text/src/Tests/Formatter/TextPlainUnitTest.php
@@ -9,7 +9,7 @@
 
 use Drupal\Core\Entity\ContentEntityInterface;
 use Drupal\Core\Entity\Display\EntityViewDisplayInterface;
-use Drupal\Core\Language\Language;
+use Drupal\Core\Language\LanguageInterface;
 use Drupal\simpletest\DrupalUnitTestBase;
 
 /**
@@ -92,7 +92,7 @@ function setUp() {
       ));
     $this->display->save();
 
-    $this->langcode = Language::LANGCODE_NOT_SPECIFIED;
+    $this->langcode = LanguageInterface::LANGCODE_NOT_SPECIFIED;
   }
 
   /**
diff --git a/core/modules/tracker/src/Tests/Views/TrackerTestBase.php b/core/modules/tracker/src/Tests/Views/TrackerTestBase.php
index a727ad5..7f20868 100644
--- a/core/modules/tracker/src/Tests/Views/TrackerTestBase.php
+++ b/core/modules/tracker/src/Tests/Views/TrackerTestBase.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\tracker\Tests\Views;
 
-use Drupal\Core\Language\Language;
+use Drupal\Core\Language\LanguageInterface;
 use Drupal\views\Tests\ViewTestBase;
 use Drupal\views\Tests\ViewTestData;
 
@@ -55,7 +55,7 @@ protected function setUp() {
       'entity_type' => 'node',
       'field_name' => 'comment',
       'subject' => $this->randomName(),
-      'comment_body[' . Language::LANGCODE_NOT_SPECIFIED . '][0][value]' => $this->randomName(20),
+      'comment_body[' . LanguageInterface::LANGCODE_NOT_SPECIFIED . '][0][value]' => $this->randomName(20),
     ));
 
   }
diff --git a/core/modules/user/src/AccountForm.php b/core/modules/user/src/AccountForm.php
index 42a2292..1180fac 100644
--- a/core/modules/user/src/AccountForm.php
+++ b/core/modules/user/src/AccountForm.php
@@ -10,7 +10,7 @@
 use Drupal\Core\Entity\ContentEntityForm;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\Entity\Query\QueryFactory;
-use Drupal\Core\Language\Language;
+use Drupal\Core\Language\LanguageInterface;
 use Drupal\Core\Language\LanguageManagerInterface;
 use Drupal\language\ConfigurableLanguageManagerInterface;
 use Drupal\user\Plugin\LanguageNegotiation\LanguageNegotiationUserAdmin;
@@ -253,7 +253,7 @@ public function form(array $form, array &$form_state) {
     $user_language_added = FALSE;
     if ($this->languageManager instanceof ConfigurableLanguageManagerInterface) {
       $negotiator = $this->languageManager->getNegotiator();
-      $user_language_added = $negotiator && $negotiator->isNegotiationMethodEnabled(LanguageNegotiationUser::METHOD_ID, Language::TYPE_INTERFACE);
+      $user_language_added = $negotiator && $negotiator->isNegotiationMethodEnabled(LanguageNegotiationUser::METHOD_ID, LanguageInterface::TYPE_INTERFACE);
     }
     $form['language'] = array(
       '#type' => $this->languageManager->isMultilingual() ? 'details' : 'container',
@@ -267,7 +267,7 @@ public function form(array $form, array &$form_state) {
     $form['language']['preferred_langcode'] = array(
       '#type' => 'language_select',
       '#title' => $this->t('Site language'),
-      '#languages' => Language::STATE_CONFIGURABLE,
+      '#languages' => LanguageInterface::STATE_CONFIGURABLE,
       '#default_value' => $user_preferred_langcode,
       '#description' => $user_language_added ? $this->t("This account's preferred language for e-mails and site presentation.") : $this->t("This account's preferred language for e-mails."),
     );
@@ -282,7 +282,7 @@ public function form(array $form, array &$form_state) {
     $form['language']['preferred_admin_langcode'] = array(
       '#type' => 'language_select',
       '#title' => $this->t('Administration pages language'),
-      '#languages' => Language::STATE_CONFIGURABLE,
+      '#languages' => LanguageInterface::STATE_CONFIGURABLE,
       '#default_value' => $user_preferred_admin_langcode,
       '#access' => $show_admin_language,
     );
diff --git a/core/modules/user/src/Tests/UserEntityTest.php b/core/modules/user/src/Tests/UserEntityTest.php
index 43bee29..9621d33 100644
--- a/core/modules/user/src/Tests/UserEntityTest.php
+++ b/core/modules/user/src/Tests/UserEntityTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\user\Tests;
 
-use Drupal\Core\Language\Language;
+use Drupal\Core\Language\LanguageInterface;
 use Drupal\simpletest\DrupalUnitTestBase;
 use Drupal\user\Entity\User;
 
@@ -46,7 +46,7 @@ public function testUserMethods() {
     $role_storage->create(array('id' => 'test_role_two'))->save();
     $role_storage->create(array('id' => 'test_role_three'))->save();
 
-    $values = array('roles' => array(Language::LANGCODE_DEFAULT => array('test_role_one')));
+    $values = array('roles' => array(LanguageInterface::LANGCODE_DEFAULT => array('test_role_one')));
     $user = new User($values, 'user');
 
     $this->assertTrue($user->hasRole('test_role_one'));
diff --git a/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php b/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php
index b960d5b..cecfcc1 100644
--- a/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php
+++ b/core/modules/views/src/Plugin/views/display/DisplayPluginBase.php
@@ -9,7 +9,7 @@
 
 use Drupal\Component\Utility\String;
 use Drupal\Core\Cache\Cache;
-use Drupal\Core\Language\Language;
+use Drupal\Core\Language\LanguageInterface;
 use Drupal\Core\Session\AccountInterface;
 use Drupal\Core\Theme\Registry;
 use Drupal\views\Plugin\views\area\AreaPluginBase;
@@ -1243,7 +1243,7 @@ public function optionsSummary(&$categories, &$options) {
     $languages = array(
         '***CURRENT_LANGUAGE***' => t("Current user's language"),
         '***DEFAULT_LANGUAGE***' => t("Default site language"),
-        Language::LANGCODE_NOT_SPECIFIED => t('Language neutral'),
+        LanguageInterface::LANGCODE_NOT_SPECIFIED => t('Language neutral'),
     );
     if (\Drupal::moduleHandler()->moduleExists('language')) {
       $languages = array_merge($languages, language_list());
@@ -1617,7 +1617,7 @@ public function buildOptionsForm(&$form, &$form_state) {
           $languages = array(
             '***CURRENT_LANGUAGE***' => t("Current user's language"),
             '***DEFAULT_LANGUAGE***' => t("Default site language"),
-            Language::LANGCODE_NOT_SPECIFIED => t('Language neutral'),
+            LanguageInterface::LANGCODE_NOT_SPECIFIED => t('Language neutral'),
           );
           $languages = array_merge($languages, views_language_list());
 
diff --git a/core/modules/views/src/Tests/DefaultViewsTest.php b/core/modules/views/src/Tests/DefaultViewsTest.php
index 6e74149..513c3b2 100644
--- a/core/modules/views/src/Tests/DefaultViewsTest.php
+++ b/core/modules/views/src/Tests/DefaultViewsTest.php
@@ -8,7 +8,7 @@
 namespace Drupal\views\Tests;
 
 use Drupal\comment\CommentInterface;
-use Drupal\Core\Language\Language;
+use Drupal\Core\Language\LanguageInterface;
 use Drupal\simpletest\WebTestBase;
 use Drupal\views\ViewExecutable;
 use Drupal\views\Views;
@@ -54,7 +54,7 @@ protected function setUp() {
       'name' => $this->randomName(),
       'description' => $this->randomName(),
       'vid' => drupal_strtolower($this->randomName()),
-      'langcode' => Language::LANGCODE_NOT_SPECIFIED,
+      'langcode' => LanguageInterface::LANGCODE_NOT_SPECIFIED,
       'help' => '',
       'nodes' => array('page' => 'page'),
       'weight' => mt_rand(0, 10),
@@ -164,7 +164,7 @@ function createTerm($vocabulary) {
       // Use the first available text format.
       'format' => $format->format,
       'vid' => $vocabulary->id(),
-      'langcode' => Language::LANGCODE_NOT_SPECIFIED,
+      'langcode' => LanguageInterface::LANGCODE_NOT_SPECIFIED,
     ));
     $term->save();
     return $term;
diff --git a/core/modules/views/src/Tests/ViewsTaxonomyAutocompleteTest.php b/core/modules/views/src/Tests/ViewsTaxonomyAutocompleteTest.php
index 766ae49..35d5f87 100644
--- a/core/modules/views/src/Tests/ViewsTaxonomyAutocompleteTest.php
+++ b/core/modules/views/src/Tests/ViewsTaxonomyAutocompleteTest.php
@@ -8,8 +8,8 @@
 namespace Drupal\views\Tests;
 
 use Drupal\Component\Utility\String;
+use Drupal\Core\Language\LanguageInterface;
 use Drupal\views\Tests\ViewTestBase;
-use Drupal\Core\Language\Language;
 
 /**
  * Tests the views taxonomy complete menu callback.
@@ -105,7 +105,7 @@ protected function createTerm($name = NULL) {
       'name' => $name ?: $this->randomName(),
       'description' => $this->randomName(),
       'vid' => $this->vocabulary->id(),
-      'langcode' => Language::LANGCODE_NOT_SPECIFIED,
+      'langcode' => LanguageInterface::LANGCODE_NOT_SPECIFIED,
     ));
     $term->save();
     return $term;
diff --git a/core/modules/views/views.api.php b/core/modules/views/views.api.php
index f1551e2..ecc9f72 100644
--- a/core/modules/views/views.api.php
+++ b/core/modules/views/views.api.php
@@ -5,6 +5,8 @@
  * Describes hooks and plugins provided by the Views module.
  */
 
+use Drupal\Core\Language\LanguageInterface;
+
 /**
  * @defgroup views_plugins Views plugins
  *
@@ -341,7 +343,7 @@ function hook_views_query_substitutions(ViewExecutable $view) {
   return array(
     '***CURRENT_VERSION***' => \Drupal::VERSION,
     '***CURRENT_TIME***' => REQUEST_TIME,
-    '***CURRENT_LANGUAGE***' => \Drupal::languageManager()->getCurrentLanguage(\Drupal\Core\Language\Language::TYPE_CONTENT)->id,
+    '***CURRENT_LANGUAGE***' => \Drupal::languageManager()->getCurrentLanguage(LanguageInterface::TYPE_CONTENT)->id,
     '***DEFAULT_LANGUAGE***' => \Drupal::languageManager()->getDefaultLanguage()->id,
   );
 }
diff --git a/core/modules/views/views.module b/core/modules/views/views.module
index 216bc93..33734c0 100644
--- a/core/modules/views/views.module
+++ b/core/modules/views/views.module
@@ -12,7 +12,7 @@
 use Drupal\Component\Utility\String;
 use Drupal\Core\Cache\Cache;
 use Drupal\Core\Database\Query\AlterableInterface;
-use Drupal\Core\Language\Language;
+use Drupal\Core\Language\LanguageInterface;
 use Drupal\Core\Render\Element;
 use Drupal\views\Plugin\Derivative\ViewsLocalTask;
 use Drupal\Core\Template\AttributeArray;
@@ -515,7 +515,7 @@ function views_add_contextual_links(&$render_element, $location, ViewExecutable
  *
  * @see locale_language_list()
  */
-function views_language_list($field = 'name', $flags = Language::STATE_ALL) {
+function views_language_list($field = 'name', $flags = LanguageInterface::STATE_ALL) {
   $languages = \Drupal::languageManager()->getLanguages($flags);
   $list = array();
   foreach ($languages as $language) {
diff --git a/core/modules/views/views.views_execution.inc b/core/modules/views/views.views_execution.inc
index d1c040f..96b5006 100644
--- a/core/modules/views/views.views_execution.inc
+++ b/core/modules/views/views.views_execution.inc
@@ -5,7 +5,7 @@
  * Provides views runtime hooks for views.module.
  */
 
-use Drupal\Core\Language\Language;
+use Drupal\Core\Language\LanguageInterface;
 use Drupal\views\ViewExecutable;
 
 /**
@@ -17,7 +17,7 @@ function views_views_query_substitutions(ViewExecutable $view) {
   return array(
     '***CURRENT_VERSION***' => \Drupal::VERSION,
     '***CURRENT_TIME***' => REQUEST_TIME,
-    '***CURRENT_LANGUAGE***' => \Drupal::languageManager()->getCurrentLanguage(Language::TYPE_CONTENT)->id,
+    '***CURRENT_LANGUAGE***' => \Drupal::languageManager()->getCurrentLanguage(LanguageInterface::TYPE_CONTENT)->id,
     '***DEFAULT_LANGUAGE***' => \Drupal::languageManager()->getDefaultLanguage()->id,
   );
 }
diff --git a/core/modules/views_ui/tests/src/ViewUIObjectTest.php b/core/modules/views_ui/tests/src/ViewUIObjectTest.php
index 7cbf7b9..f105b3a 100644
--- a/core/modules/views_ui/tests/src/ViewUIObjectTest.php
+++ b/core/modules/views_ui/tests/src/ViewUIObjectTest.php
@@ -7,7 +7,7 @@
 
 namespace Drupal\views_ui\Tests;
 
-use Drupal\Core\Language\Language;
+use Drupal\Core\Language\LanguageInterface;
 use Drupal\Tests\UnitTestCase;
 use Drupal\views\ViewExecutable;
 use Drupal\views_ui\ViewUI;
@@ -37,7 +37,7 @@ public function testEntityDecoration() {
     $method_args['setOriginalId'] = array(12);
     $method_args['setStatus'] = array(TRUE);
     $method_args['enforceIsNew'] = array(FALSE);
-    $method_args['label'] = array(Language::LANGCODE_NOT_SPECIFIED);
+    $method_args['label'] = array(LanguageInterface::LANGCODE_NOT_SPECIFIED);
 
     $reflection = new \ReflectionClass('Drupal\Core\Config\Entity\ConfigEntityInterface');
     $interface_methods = array();