diff --git a/core/modules/block/config/schema/block.schema.yml b/core/modules/block/config/schema/block.schema.yml
index f755df3..089889b 100644
--- a/core/modules/block/config/schema/block.schema.yml
+++ b/core/modules/block/config/schema/block.schema.yml
@@ -7,6 +7,9 @@ block.block.*.*:
     id:
       type: string
       label: 'ID'
+    uuid:
+      type: string
+      label: 'UUID'
     label:
       type: label
       label: 'Title'
diff --git a/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTest.php b/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTest.php
index a204a32..c763964 100644
--- a/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTest.php
@@ -89,6 +89,10 @@ function testSchemaMapping() {
       'label' =>  'Message to display when in maintenance mode',
       'type' => 'text',
     );
+    $expected['mapping']['langcode'] = array(
+      'label' =>  'Default language',
+      'type' => 'string',
+    );
     $this->assertEqual($definition, $expected, 'Retrieved the right metadata for system.maintenance');
 
     // More complex case, generic type. Metadata for image style.
@@ -104,6 +108,8 @@ function testSchemaMapping() {
     $expected['mapping']['effects']['sequence'][0]['mapping']['data']['type'] = 'image.effect.[%parent.name]';
     $expected['mapping']['effects']['sequence'][0]['mapping']['weight']['type'] = 'integer';
     $expected['mapping']['effects']['sequence'][0]['mapping']['ieid']['type'] = 'string';
+    $expected['mapping']['langcode']['label'] =  'Default language';
+    $expected['mapping']['langcode']['type'] = 'string';
 
     $this->assertEqual($definition, $expected, 'Retrieved the right metadata for image.style.large');
 
diff --git a/core/modules/contact/config/schema/contact.schema.yml b/core/modules/contact/config/schema/contact.schema.yml
index 7f19bf8..c853697 100644
--- a/core/modules/contact/config/schema/contact.schema.yml
+++ b/core/modules/contact/config/schema/contact.schema.yml
@@ -7,6 +7,9 @@ contact.category.*:
     id:
       type: string
       label: 'Category identifier'
+    uuid:
+      type: string
+      label: 'UUID'
     label:
       type: label
       label: 'Label'
@@ -22,6 +25,12 @@ contact.category.*:
     weight:
       type: integer
       label: 'Weight'
+    status:
+      type: boolean
+      label: 'Status'
+    langcode:
+      type: string
+      label: 'Default language'
 
 contact.settings:
   type: mapping
diff --git a/core/modules/image/config/schema/image.schema.yml b/core/modules/image/config/schema/image.schema.yml
index 0bb8d5d..fe9cf83 100644
--- a/core/modules/image/config/schema/image.schema.yml
+++ b/core/modules/image/config/schema/image.schema.yml
@@ -34,6 +34,10 @@ image.style.*:
               type: integer
             ieid:
               type: string
+    langcode:
+      type: string
+      label: 'Default language'
+
 
 # Image effects plugins: image.effect.%
 # These are used in image styles.
diff --git a/core/modules/shortcut/config/schema/shortcut.schema.yml b/core/modules/shortcut/config/schema/shortcut.schema.yml
index 048d1a5..ace2525 100644
--- a/core/modules/shortcut/config/schema/shortcut.schema.yml
+++ b/core/modules/shortcut/config/schema/shortcut.schema.yml
@@ -1,12 +1,18 @@
 # Schema for the configuration files of the Shortcut module.
 
-shortcut.set.default:
+shortcut.set.*:
   type: mapping
   label: 'Shortcut settings'
   mapping:
     id:
       type: string
       label: 'ID'
+    uuid:
+      type: string
+      label: 'UUID'
     label:
       type: label
       label: 'Label'
+    langcode:
+      type: string
+      label: 'Default language'
diff --git a/core/modules/system/config/schema/system.schema.yml b/core/modules/system/config/schema/system.schema.yml
index 754ec01..ca4302f 100644
--- a/core/modules/system/config/schema/system.schema.yml
+++ b/core/modules/system/config/schema/system.schema.yml
@@ -32,6 +32,9 @@ system.site:
     weight_select_max:
       type: integer
       label: 'Weight element maximum value'
+    langcode:
+      type: string
+      label: 'Default language'
 
 system.maintenance:
   type: mapping
@@ -43,6 +46,9 @@ system.maintenance:
     message:
       type: text
       label: 'Message to display when in maintenance mode'
+    langcode:
+      type: string
+      label: 'Default language'
 
 system.authorize:
   type: mapping
@@ -90,6 +96,9 @@ system.date:
       sequence:
         - type: date_format
           label: 'Date format'
+    langcode:
+      type: string
+      label: 'Default language'
 
 
 system.fast_404:
@@ -212,6 +221,9 @@ system.rss:
         view_mode:
           type: string
           label: 'Feed content'
+    langcode:
+      type: string
+      label: 'Default language'
 
 system.theme:
   type: mapping
@@ -261,3 +273,6 @@ menu.menu.*:
     description:
       type: label
       label: 'Menu description'
+    langcode:
+      type: string
+      label: 'Default language'
diff --git a/core/modules/system/config/system.maintenance.yml b/core/modules/system/config/system.maintenance.yml
index 04d92a8..5ea379d 100644
--- a/core/modules/system/config/system.maintenance.yml
+++ b/core/modules/system/config/system.maintenance.yml
@@ -1,2 +1,3 @@
 enabled: '0'
-message: @site is currently under maintenance. We should be back shortly. Thank you for your patience.
+message: '@site is currently under maintenance. We should be back shortly. Thank you for your patience.'
+langcode: en
diff --git a/core/modules/system/config/system.rss.yml b/core/modules/system/config/system.rss.yml
index 69e64da..1cb2f72 100644
--- a/core/modules/system/config/system.rss.yml
+++ b/core/modules/system/config/system.rss.yml
@@ -3,3 +3,4 @@ channel:
 items:
   limit: '10'
   view_mode: rss
+langcode: en
diff --git a/core/modules/system/config/system.site.yml b/core/modules/system/config/system.site.yml
index b642dc8..0c9a56b 100644
--- a/core/modules/system/config/system.site.yml
+++ b/core/modules/system/config/system.site.yml
@@ -7,3 +7,4 @@ page:
   front: user
 admin_compact_mode: '0'
 weight_select_max: '100'
+langcode: en
diff --git a/core/modules/user/config/schema/user.schema.yml b/core/modules/user/config/schema/user.schema.yml
index d5ba6cc..989abae 100644
--- a/core/modules/user/config/schema/user.schema.yml
+++ b/core/modules/user/config/schema/user.schema.yml
@@ -56,6 +56,9 @@ user.settings:
     password_strength:
       type: boolean
       label: 'Enable password strength indicator'
+    langcode:
+      type: string
+      label: 'Default language'
 
 user.mail:
  type: mapping
@@ -88,6 +91,9 @@ user.mail:
   status_canceled:
     type: mail
     label: 'Account cancelled'
+  langcode:
+    type: string
+    label: 'Default language'
 
 user.flood:
   type: mapping
@@ -116,9 +122,15 @@ user.role.*:
     id:
       type: string
       label: 'User role ID'
+    uuid:
+      type: string
+      label: 'UUID'
     label:
       type: label
       label: 'User role label'
     weight:
       type: integer
       label: 'User role weight'
+    langcode:
+      type: string
+      label: 'Default language'
diff --git a/core/modules/user/config/user.mail.yml b/core/modules/user/config/user.mail.yml
index 7367e46..ea33738 100644
--- a/core/modules/user/config/user.mail.yml
+++ b/core/modules/user/config/user.mail.yml
@@ -25,3 +25,4 @@ status_blocked:
 status_canceled:
   body: "[user:name],\n\nYour account on [site:name] has been canceled.\n\n--  [site:name] team"
   subject: 'Account details for [user:name] at [site:name] (canceled)'
+langcode: en
diff --git a/core/modules/user/config/user.settings.yml b/core/modules/user/config/user.settings.yml
index 3b53e41..bdb3408 100644
--- a/core/modules/user/config/user.settings.yml
+++ b/core/modules/user/config/user.settings.yml
@@ -15,3 +15,4 @@ signatures: '0'
 cancel_method: user_cancel_block
 password_reset_timeout: '86400'
 password_strength: '1'
+langcode: en
diff --git a/core/modules/views/config/schema/views.schema.yml b/core/modules/views/config/schema/views.schema.yml
index 3fa15fc..74bab51 100644
--- a/core/modules/views/config/schema/views.schema.yml
+++ b/core/modules/views/config/schema/views.schema.yml
@@ -47,6 +47,9 @@ views.view.*:
               label: 'Position'
             display_options:
               type: 'views.display.[%parent.display_plugin]'
+    langcode:
+      type: string
+      label: 'Default language'
 
 # Views display: common
 # Options for Drupal\views\Plugin\views\display\DisplayPluginBase