diff --git a/core/lib/Drupal/Core/Language/Language.php b/core/lib/Drupal/Core/Language/Language.php
index cf2248b..8c343c8 100644
--- a/core/lib/Drupal/Core/Language/Language.php
+++ b/core/lib/Drupal/Core/Language/Language.php
@@ -213,6 +213,13 @@ public function setNegotiationMethodId($method_id) {
   }
 
   /**
+   * {@inheritdoc}
+   */
+  public function getCacheTag() {
+    return array('langcode' => $this->getId());
+  }
+
+  /**
    * Sort language objects.
    *
    * @param array $languages
diff --git a/core/lib/Drupal/Core/Language/LanguageInterface.php b/core/lib/Drupal/Core/Language/LanguageInterface.php
index e718749..2b53d85 100644
--- a/core/lib/Drupal/Core/Language/LanguageInterface.php
+++ b/core/lib/Drupal/Core/Language/LanguageInterface.php
@@ -208,4 +208,12 @@ public function getNegotiationMethodId();
    */
   public function setNegotiationMethodId($method_id);
 
+  /**
+   * The unique cache tag associated with this language.
+   *
+   * @return array
+   *   An array containing the language cache tag.
+   */
+  public function getCacheTag();
+
 }
diff --git a/core/modules/block/src/BlockBase.php b/core/modules/block/src/BlockBase.php
index a2f5e17..cf153c0 100644
--- a/core/modules/block/src/BlockBase.php
+++ b/core/modules/block/src/BlockBase.php
@@ -447,7 +447,10 @@ public function getCacheTags() {
     // cache tag that affects all instances of this block: across themes and
     // across regions.
     $block_plugin_cache_tag = str_replace(':', '__', $this->getPluginID());
-    return array('block_plugin' => array($block_plugin_cache_tag));
+    return array_merge(
+      array('block_plugin' => array($block_plugin_cache_tag)),
+      \Drupal::languageManager()->getCurrentLanguage()->getCacheTag()
+    );
   }
 
   /**
diff --git a/core/modules/block/src/Tests/BlockTest.php b/core/modules/block/src/Tests/BlockTest.php
index ebd4a7c..9539880 100644
--- a/core/modules/block/src/Tests/BlockTest.php
+++ b/core/modules/block/src/Tests/BlockTest.php
@@ -297,6 +297,7 @@ public function testBlockCacheTags() {
       'block_view:1',
       'block:powered',
       'block_plugin:system_powered_by_block',
+      'langcode:en',
       'rendered:1',
     );
     $this->assertIdentical($cache_entry->tags, $expected_cache_tags);
@@ -306,6 +307,7 @@ public function testBlockCacheTags() {
       'block:powered',
       'theme:stark',
       'block_plugin:system_powered_by_block',
+      'langcode:en',
       'rendered:1',
     );
     $this->assertIdentical($cache_entry->tags, $expected_cache_tags);
@@ -338,6 +340,7 @@ public function testBlockCacheTags() {
       'block:powered-2',
       'block:powered',
       'block_plugin:system_powered_by_block',
+      'langcode:en',
       'rendered:1',
     );
     $this->assertEqual($cache_entry->tags, $expected_cache_tags);
@@ -346,6 +349,7 @@ public function testBlockCacheTags() {
       'block:powered',
       'theme:stark',
       'block_plugin:system_powered_by_block',
+      'langcode:en',
       'rendered:1',
     );
     $cache_entry = \Drupal::cache('render')->get('entity_view:block:powered:en:stark');
@@ -355,6 +359,7 @@ public function testBlockCacheTags() {
       'block:powered-2',
       'theme:stark',
       'block_plugin:system_powered_by_block',
+      'langcode:en',
       'rendered:1',
     );
     $cache_entry = \Drupal::cache('render')->get('entity_view:block:powered-2:en:stark');
diff --git a/core/modules/block/src/Tests/BlockViewBuilderTest.php b/core/modules/block/src/Tests/BlockViewBuilderTest.php
index 38969e8..b7ec21a 100644
--- a/core/modules/block/src/Tests/BlockViewBuilderTest.php
+++ b/core/modules/block/src/Tests/BlockViewBuilderTest.php
@@ -219,7 +219,7 @@ public function testBlockViewBuilderAlter() {
     $request->setMethod('GET');
 
     $default_keys = array('entity_view', 'block', 'test_block', 'en', 'cache_context.theme');
-    $default_tags = array('block_view' => TRUE, 'block' => array('test_block'), 'theme' => 'stark', 'block_plugin' => array('test_cache'));
+    $default_tags = array('block_view' => TRUE, 'block' => array('test_block'), 'theme' => 'stark', 'block_plugin' => array('test_cache'), 'langcode' => 'en');
 
     // Advanced: cached block, but an alter hook adds an additional cache key.
     $this->setBlockCacheConfig(array(
@@ -234,7 +234,7 @@ public function testBlockViewBuilderAlter() {
     $this->assertIdentical(drupal_render($build), '');
     $cache_entry = $this->container->get('cache.render')->get($cid);
     $this->assertTrue($cache_entry, 'The block render element has been cached with the expected cache ID.');
-    $expected_flattened_tags = array('block_view:1', 'block:test_block', 'theme:stark', 'block_plugin:test_cache', 'rendered:1');
+    $expected_flattened_tags = array('block_view:1', 'block:test_block', 'theme:stark', 'block_plugin:test_cache','langcode:en', 'rendered:1');
     $this->assertIdentical($cache_entry->tags, $expected_flattened_tags, 'The block render element has been cached with the expected cache tags.');
     $this->container->get('cache.render')->delete($cid);
 
@@ -248,7 +248,7 @@ public function testBlockViewBuilderAlter() {
     $this->assertIdentical(drupal_render($build), '');
     $cache_entry = $this->container->get('cache.render')->get($cid);
     $this->assertTrue($cache_entry, 'The block render element has been cached with the expected cache ID.');
-    $expected_flattened_tags = array('block_view:1', 'block:test_block', 'theme:stark', 'block_plugin:test_cache', $alter_add_tag . ':1', 'rendered:1');
+    $expected_flattened_tags = array('block_view:1', 'block:test_block', 'theme:stark', 'block_plugin:test_cache', 'langcode:en', $alter_add_tag . ':1', 'rendered:1');
     $this->assertIdentical($cache_entry->tags, $expected_flattened_tags, 'The block render element has been cached with the expected cache tags.');
     $this->container->get('cache.render')->delete($cid);
 
diff --git a/core/modules/config_translation/src/Form/ConfigTranslationFormBase.php b/core/modules/config_translation/src/Form/ConfigTranslationFormBase.php
index d3d63be..c35077e 100644
--- a/core/modules/config_translation/src/Form/ConfigTranslationFormBase.php
+++ b/core/modules/config_translation/src/Form/ConfigTranslationFormBase.php
@@ -8,6 +8,7 @@
 namespace Drupal\config_translation\Form;
 
 use Drupal\config_translation\ConfigMapperManagerInterface;
+use Drupal\Core\Cache\Cache;
 use Drupal\Core\Config\Config;
 use Drupal\Core\Config\Schema\Element;
 use Drupal\Core\Config\TypedConfigManagerInterface;
@@ -235,6 +236,8 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
       $this->mapper->getOverviewRoute(),
       $this->mapper->getOverviewRouteParameters()
     );
+
+    Cache::invalidateTags($this->language->getCacheTag());
   }
 
   /**
diff --git a/core/modules/menu_ui/src/Tests/MenuCacheTagsTest.php b/core/modules/menu_ui/src/Tests/MenuCacheTagsTest.php
index 4a19182..ef451e7 100644
--- a/core/modules/menu_ui/src/Tests/MenuCacheTagsTest.php
+++ b/core/modules/menu_ui/src/Tests/MenuCacheTagsTest.php
@@ -50,6 +50,7 @@ public function testMenuBlock() {
     $expected_tags = array(
       'theme:stark',
       'theme_global_settings:1',
+      'langcode:en',
       'rendered:1',
       'block_view:1',
       'block:' . $block->id(),
diff --git a/core/modules/system/src/Tests/Cache/PageCacheTagsIntegrationTest.php b/core/modules/system/src/Tests/Cache/PageCacheTagsIntegrationTest.php
index 6dbfb51..c00644c 100644
--- a/core/modules/system/src/Tests/Cache/PageCacheTagsIntegrationTest.php
+++ b/core/modules/system/src/Tests/Cache/PageCacheTagsIntegrationTest.php
@@ -68,6 +68,7 @@ function testPageCacheTags() {
 
     // Full node page 1.
     $this->verifyPageCacheTags('node/' . $node_1->id(), array(
+      'langcode:en',
       'rendered:1',
       'theme:bartik',
       'theme_global_settings:1',
@@ -93,6 +94,7 @@ function testPageCacheTags() {
 
     // Full node page 2.
     $this->verifyPageCacheTags('node/' . $node_2->id(), array(
+      'langcode:en',
       'rendered:1',
       'theme:bartik',
       'theme_global_settings:1',