diff --git a/core/modules/aggregator/src/Tests/FeedLanguageTest.php b/core/modules/aggregator/src/Tests/FeedLanguageTest.php
index a5ce7a2..09c608c 100644
--- a/core/modules/aggregator/src/Tests/FeedLanguageTest.php
+++ b/core/modules/aggregator/src/Tests/FeedLanguageTest.php
@@ -43,8 +43,6 @@ protected function setUp() {
       $language->save();
       $this->langcodes[$i] = $language->id();
     }
-
-    language_save_default_configuration('aggregator_feed', 'aggregator_feed', array('langcode' => 'site_default', 'language_show' => TRUE));
   }
 
   /**
@@ -54,8 +52,8 @@ public function testFeedLanguage() {
     /** @var \Drupal\aggregator\FeedInterface[] $feeds */
     $feeds = array();
     // Create feeds.
-    $feeds[1] = $this->createFeed(NULL, array('langcode[0][value]' => $this->langcodes[1]));
-    $feeds[2] = $this->createFeed(NULL, array('langcode[0][value]' => $this->langcodes[2]));
+    $feeds[1] = $this->createFeed(NULL, array('langcode' => $this->langcodes[1]));
+    $feeds[2] = $this->createFeed(NULL, array('langcode' => $this->langcodes[2]));
 
     // Make sure that the language has been assigned.
     $this->assertEqual($feeds[1]->language()->getId(), $this->langcodes[1]);
diff --git a/core/modules/content_translation/src/Tests/ContentTranslationTestBase.php b/core/modules/content_translation/src/Tests/ContentTranslationTestBase.php
index 981c3ed..e52036b 100644
--- a/core/modules/content_translation/src/Tests/ContentTranslationTestBase.php
+++ b/core/modules/content_translation/src/Tests/ContentTranslationTestBase.php
@@ -163,7 +163,6 @@ protected function setupBundle() {
   protected function enableTranslation() {
     // Enable translation for the current entity type and ensure the change is
     // picked up.
-    language_save_default_configuration($this->entityTypeId, $this->bundle, array('langcode' => 'site_default', 'language_show' => TRUE));
     content_translation_set_config($this->entityTypeId, $this->bundle, 'enabled', TRUE);
     drupal_static_reset();
     \Drupal::entityManager()->clearCachedDefinitions();
diff --git a/core/modules/content_translation/src/Tests/ContentTranslationUITest.php b/core/modules/content_translation/src/Tests/ContentTranslationUITest.php
index d9c695d..5e8497b 100644
--- a/core/modules/content_translation/src/Tests/ContentTranslationUITest.php
+++ b/core/modules/content_translation/src/Tests/ContentTranslationUITest.php
@@ -8,6 +8,7 @@
 namespace Drupal\content_translation\Tests;
 
 use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\ContentEntityBase;
 use Drupal\Core\Language\Language;
 use Drupal\Core\Language\LanguageInterface;
 
diff --git a/core/modules/locale/src/Tests/LocaleContentTest.php b/core/modules/locale/src/Tests/LocaleContentTest.php
index 1bef062..f9f43f0 100644
--- a/core/modules/locale/src/Tests/LocaleContentTest.php
+++ b/core/modules/locale/src/Tests/LocaleContentTest.php
@@ -95,12 +95,12 @@ public function testContentTypeLanguageConfiguration() {
     $this->drupalLogin($web_user);
     $this->drupalGet("node/add/{$type1->type}");
     // Verify language select list is not present.
-    $this->assertNoFieldByName('language', NULL, 'Language select not present on the node add form.');
+    $this->assertNoFieldByName('langcode[0][value]', NULL, 'Language select not present on the node add form.');
 
     // Verify language selection appears on the node add form.
     $this->drupalGet("node/add/{$type2->type}");
     // Verify language select list is present.
-    $this->assertFieldByName('langcode', NULL, 'Language select present on the node add form.');
+    $this->assertFieldByName('langcode[0][value]', NULL, 'Language select present on the node add form.');
     // Ensure language appears.
     $this->assertText($name, 'Language present.');
 
@@ -120,7 +120,7 @@ public function testContentTypeLanguageConfiguration() {
     $this->assertRaw('<option value="' . $langcode . '" selected="selected">' .  $name . '</option>', 'Correct language selected.');
     // Ensure we can change the node language.
     $edit = array(
-      'langcode' => 'en',
+      'langcode[0][value]' => 'en',
     );
     $this->drupalPostForm($path, $edit, t('Save'));
     $this->assertRaw(t('%title has been updated.', array('%title' => $node_title)));
diff --git a/core/modules/menu_ui/src/Tests/MenuLanguageTest.php b/core/modules/menu_ui/src/Tests/MenuLanguageTest.php
index f74fb09..0664b81 100644
--- a/core/modules/menu_ui/src/Tests/MenuLanguageTest.php
+++ b/core/modules/menu_ui/src/Tests/MenuLanguageTest.php
@@ -105,7 +105,7 @@ function testMenuLanguage() {
 
     // Now change the language of the new link to 'bb'.
     $edit = array(
-      'langcode' => 'bb',
+      'langcode[0][value]' => 'bb',
     );
     $this->drupalPostForm('admin/structure/menu/item/' . $menu_link->id() . '/edit', $edit, t('Save'));
     $this->assertMenuLink($menu_link->getPluginId(), array(
@@ -119,14 +119,14 @@ function testMenuLanguage() {
     // page first.
     $this->drupalGet('admin/structure/menu/item/' . $menu_link->id() . '/edit');
     // Check that the language selector has the correct default value.
-    $this->assertOptionSelected('edit-langcode', 'bb', 'The menu link language was correctly selected.');
+    $this->assertOptionSelected('edit-langcode-0-value', 'bb', 'The menu link language was correctly selected.');
 
     // Edit menu to hide the language select on menu link item add.
      language_save_default_configuration('menu_link_content', 'menu_link_content',  array('langcode' => 'cc', 'language_show' => FALSE));
 
     // Check that the language selector is not available on menu link add page.
     $this->drupalGet("admin/structure/menu/manage/$menu_name/add");
-    $this->assertNoField('edit-langcode', 'The language selector field was hidden the page');
+    $this->assertNoField('edit-langcode-0-value', 'The language selector field was hidden the page');
   }
 
   /**
diff --git a/core/modules/node/src/Tests/NodeFieldMultilingualTest.php b/core/modules/node/src/Tests/NodeFieldMultilingualTest.php
index d00ffcd..1e2c731 100644
--- a/core/modules/node/src/Tests/NodeFieldMultilingualTest.php
+++ b/core/modules/node/src/Tests/NodeFieldMultilingualTest.php
@@ -84,7 +84,7 @@ function testMultilingualNodeForm() {
     $this->drupalGet("node/{$node->id()}/edit");
     $edit = array(
       $title_key => $this->randomMachineName(8),
-      'langcode' => $langcode,
+      'langcode[0][value]' => $langcode,
     );
     $this->drupalPostForm(NULL, $edit, t('Save'));
     $node = $this->drupalGetNodeByTitle($edit[$title_key], TRUE);
diff --git a/core/modules/system/src/Tests/Entity/EntityTranslationFormTest.php b/core/modules/system/src/Tests/Entity/EntityTranslationFormTest.php
index 59da34d..b3e3351 100644
--- a/core/modules/system/src/Tests/Entity/EntityTranslationFormTest.php
+++ b/core/modules/system/src/Tests/Entity/EntityTranslationFormTest.php
@@ -89,7 +89,7 @@ function testEntityFormLanguage() {
     $langcode = $this->langcodes[0];
     $edit['title[0][value]'] = $this->randomMachineName(8);
     $edit['body[0][value]'] = $this->randomMachineName(16);
-    $edit['langcode'] = $langcode;
+    $edit['langcode[0][value]'] = $langcode;
     $this->drupalPostForm('node/add/page', $edit, t('Save'));
     $this->assertRaw(t('Basic page %title has been created.', array('%title' => $edit['title[0][value]'])), 'Basic page created.');
 
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 89b5f6e..c583c46 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
@@ -76,12 +76,8 @@ public static function baseFieldDefinitions(EntityTypeInterface $entity_type) {
       ->setReadOnly(TRUE);
 
     $fields['langcode'] = BaseFieldDefinition::create('language')
-      ->setLabel(t('Language'))
-      ->setDescription(t('The language code of the test entity.'))
-      ->setDisplayOptions('form', array(
-        'type' => 'language_select',
-        'weight' => 2,
-      ));
+      ->setLabel(t('Language code'))
+      ->setDescription(t('The language code of the test entity.'));
 
     $fields['name'] = BaseFieldDefinition::create('string')
       ->setLabel(t('Name'))
diff --git a/core/modules/taxonomy/src/Tests/TermLanguageTest.php b/core/modules/taxonomy/src/Tests/TermLanguageTest.php
index 71cacee..0504751 100644
--- a/core/modules/taxonomy/src/Tests/TermLanguageTest.php
+++ b/core/modules/taxonomy/src/Tests/TermLanguageTest.php
@@ -48,28 +48,28 @@ function testTermLanguage() {
     // Add a term.
     $this->drupalGet('admin/structure/taxonomy/manage/' . $this->vocabulary->id() . '/add');
     // Check that we have the language selector.
-    $this->assertField('edit-langcode', t('The language selector field was found on the page.'));
+    $this->assertField('edit-langcode-0-value', t('The language selector field was found on the page.'));
     // Submit the term.
     $edit = array(
       'name[0][value]' => $this->randomMachineName(),
-      'langcode' => 'aa',
+      'langcode[0][value]' => 'aa',
     );
     $this->drupalPostForm(NULL, $edit, t('Save'));
     $terms = taxonomy_term_load_multiple_by_name($edit['name[0][value]']);
     $term = reset($terms);
-    $this->assertEqual($term->language()->getId(), $edit['langcode'], 'The term contains the correct langcode.');
+    $this->assertEqual($term->language()->getId(), $edit['langcode[0][value]'], 'The term contains the correct langcode.');
 
     // Check if on the edit page the language is correct.
     $this->drupalGet('taxonomy/term/' . $term->id() . '/edit');
-    $this->assertOptionSelected('edit-langcode', $edit['langcode'], 'The term language was correctly selected.');
+    $this->assertOptionSelected('edit-langcode-0-value', $edit['langcode[0][value]'], 'The term language was correctly selected.');
 
     // Change the language of the term.
-    $edit['langcode'] = 'bb';
+    $edit['langcode[0][value]'] = 'bb';
     $this->drupalPostForm('taxonomy/term/' . $term->id() . '/edit', $edit, t('Save'));
 
     // Check again that on the edit page the language is correct.
     $this->drupalGet('taxonomy/term/' . $term->id() . '/edit');
-    $this->assertOptionSelected('edit-langcode', $edit['langcode'], 'The term language was correctly selected.');
+    $this->assertOptionSelected('edit-langcode-0-value', $edit['langcode[0][value]'], 'The term language was correctly selected.');
   }
 
   function testDefaultTermLanguage() {
@@ -81,7 +81,7 @@ function testDefaultTermLanguage() {
     );
     $this->drupalPostForm('admin/structure/taxonomy/manage/' . $this->vocabulary->id(), $edit, t('Save'));
     $this->drupalGet('admin/structure/taxonomy/manage/' . $this->vocabulary->id() . '/add');
-    $this->assertOptionSelected('edit-langcode', 'bb', 'The expected langcode was selected.');
+    $this->assertOptionSelected('edit-langcode-0-value', 'bb', 'The expected langcode was selected.');
 
     // Make the default language of the terms to be the current interface.
     $edit = array(
@@ -90,9 +90,9 @@ function testDefaultTermLanguage() {
     );
     $this->drupalPostForm('admin/structure/taxonomy/manage/' . $this->vocabulary->id(), $edit, t('Save'));
     $this->drupalGet('aa/admin/structure/taxonomy/manage/' . $this->vocabulary->id() . '/add');
-    $this->assertOptionSelected('edit-langcode', 'aa', "The expected langcode, 'aa', was selected.");
+    $this->assertOptionSelected('edit-langcode-0-value', 'aa', "The expected langcode, 'aa', was selected.");
     $this->drupalGet('bb/admin/structure/taxonomy/manage/' . $this->vocabulary->id() . '/add');
-    $this->assertOptionSelected('edit-langcode', 'bb', "The expected langcode, 'bb', was selected.");
+    $this->assertOptionSelected('edit-langcode-0-value', 'bb', "The expected langcode, 'bb', was selected.");
 
     // Change the default language of the site and check if the default terms
     // language is still correctly selected.
@@ -103,6 +103,6 @@ function testDefaultTermLanguage() {
     );
     $this->drupalPostForm('admin/structure/taxonomy/manage/' . $this->vocabulary->id(), $edit, t('Save'));
     $this->drupalGet('admin/structure/taxonomy/manage/' . $this->vocabulary->id() . '/add');
-    $this->assertOptionSelected('edit-langcode', 'cc', "The expected langcode, 'cc', was selected.");
+    $this->assertOptionSelected('edit-langcode-0-value', 'cc', "The expected langcode, 'cc', was selected.");
   }
 }