diff --git a/core/config/schema/core.data_types.schema.yml b/core/config/schema/core.data_types.schema.yml
index 95d6658..4ab0fd7 100644
--- a/core/config/schema/core.data_types.schema.yml
+++ b/core/config/schema/core.data_types.schema.yml
@@ -87,12 +87,22 @@ color_hex:
 # Complex extended data types:
 
 # Root of a configuration object.
+
+_core_config_info:
+  type: mapping
+  mapping:
+    default_config_hash:
+      type: string
+      label: 'Default configuration hash'
+
 config_object:
   type: mapping
   mapping:
     langcode:
       type: string
       label: 'Language code'
+    _core:
+      type: _core_config_info
 
 # Mail text with subject and body parts.
 mail:
@@ -281,9 +291,8 @@ config_entity:
       label: 'Third party settings'
       sequence:
         type: '[%parent.%parent.%type].third_party.[%key]'
-    default_config_hash:
-      type: string
-      label: 'Default configuration hash'
+    _core:
+      type: _core_config_info
 
 block_settings:
   type: mapping
diff --git a/core/lib/Drupal/Core/Config/ConfigInstaller.php b/core/lib/Drupal/Core/Config/ConfigInstaller.php
index b34dc80..04f517d 100644
--- a/core/lib/Drupal/Core/Config/ConfigInstaller.php
+++ b/core/lib/Drupal/Core/Config/ConfigInstaller.php
@@ -280,6 +280,9 @@ protected function createConfiguration($collection, array $config_to_create) {
       }
       if ($config_to_create[$name] !== FALSE) {
         $new_config->setData($config_to_create[$name]);
+        if (!$this->isSyncing()) {
+          $new_config->set('_core.default_config_hash', Crypt::hashBase64(serialize($config_to_create[$name])));
+        }
       }
       if ($collection == StorageInterface::DEFAULT_COLLECTION && $entity_type = $this->configManager->getEntityTypeIdByName($name)) {
         // If we are syncing do not create configuration entities. Pluggable
@@ -306,10 +309,7 @@ protected function createConfiguration($collection, array $config_to_create) {
           $entity = $entity_storage->createFromStorageRecord($new_config->get());
         }
         if ($entity->isInstallable()) {
-          $entity
-            ->set('default_config_hash', Crypt::hashBase64(serialize($new_config->get())))
-            ->trustData()
-            ->save();
+          $entity->trustData()->save();
         }
       }
       else {
diff --git a/core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php b/core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php
index 70144d2..8c0c376 100644
--- a/core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php
+++ b/core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php
@@ -104,9 +104,15 @@
   protected $third_party_settings = array();
 
   /**
-   * @var string
+   * Information maintained by Drupal core about configuration.
+   *
+   * Keys:
+   * - default_config_hash: A hash calculated by the config.installer service
+   *   and added during installation.
+   *
+   * @var array
    */
-  protected $default_config_hash = '';
+  protected $_core = [];
 
   /**
    * Trust supplied data and not use configuration schema on save.
@@ -301,8 +307,8 @@ public function toArray() {
     if (empty($this->third_party_settings)) {
       unset($properties['third_party_settings']);
     }
-    if (empty($this->default_config_hash)) {
-      unset($properties['default_config_hash']);
+    if (empty($this->_core)) {
+      unset($properties['_core']);
     }
     return $properties;
   }
diff --git a/core/lib/Drupal/Core/Config/Entity/ConfigEntityType.php b/core/lib/Drupal/Core/Config/Entity/ConfigEntityType.php
index b29f803..785b314 100644
--- a/core/lib/Drupal/Core/Config/Entity/ConfigEntityType.php
+++ b/core/lib/Drupal/Core/Config/Entity/ConfigEntityType.php
@@ -157,7 +157,7 @@ public function getPropertiesToExport() {
           'status' => 'status',
           'dependencies' => 'dependencies',
           'third_party_settings' => 'third_party_settings',
-          'default_config_hash' => 'default_config_hash',
+          '_core' => '_core',
         ];
         foreach ($this->config_export as $property => $name) {
           if (is_numeric($property)) {
diff --git a/core/modules/config/src/Tests/ConfigSchemaTest.php b/core/modules/config/src/Tests/ConfigSchemaTest.php
index 3c7980c..8735db1 100644
--- a/core/modules/config/src/Tests/ConfigSchemaTest.php
+++ b/core/modules/config/src/Tests/ConfigSchemaTest.php
@@ -63,6 +63,7 @@ function testSchemaMapping() {
     $expected['class'] = '\Drupal\Core\Config\Schema\Mapping';
     $expected['mapping']['langcode']['type'] = 'string';
     $expected['mapping']['langcode']['label'] = 'Language code';
+    $expected['mapping']['_core']['type'] = '_core_config_info';
     $expected['mapping']['testitem'] = array('label' => 'Test item');
     $expected['mapping']['testlist'] = array('label' => 'Test list');
     $expected['type'] = 'config_schema_test.someschema';
@@ -106,6 +107,7 @@ function testSchemaMapping() {
       'label' => 'Language code',
       'type' => 'string',
     );
+    $expected['mapping']['_core']['type'] = '_core_config_info';
     $expected['type'] = 'system.maintenance';
     $expected['definition_class'] = '\Drupal\Core\TypedData\MapDataDefinition';
     $this->assertEqual($definition, $expected, 'Retrieved the right metadata for system.maintenance');
@@ -120,6 +122,7 @@ function testSchemaMapping() {
       'type' => 'string',
       'label' => 'Language code',
     );
+    $expected['mapping']['_core']['type'] = '_core_config_info';
     $expected['mapping']['label'] = array(
       'label' =>  'Label',
       'type' => 'label',
@@ -179,8 +182,7 @@ function testSchemaMapping() {
     $expected['mapping']['third_party_settings']['type'] = 'sequence';
     $expected['mapping']['third_party_settings']['label'] = 'Third party settings';
     $expected['mapping']['third_party_settings']['sequence']['type'] = '[%parent.%parent.%type].third_party.[%key]';
-    $expected['mapping']['default_config_hash']['type'] = 'string';
-    $expected['mapping']['default_config_hash']['label'] = 'Default configuration hash';
+    $expected['mapping']['_core']['type'] = '_core_config_info';
     $expected['type'] = 'image.style.*';
 
     $this->assertEqual($definition, $expected);
@@ -233,6 +235,7 @@ function testSchemaMapping() {
     $expected['class'] = '\Drupal\Core\Config\Schema\Mapping';
     $expected['mapping']['langcode']['type'] = 'string';
     $expected['mapping']['langcode']['label'] = 'Language code';
+    $expected['mapping']['_core']['type'] = '_core_config_info';
     $expected['mapping']['testid']['type'] = 'string';
     $expected['mapping']['testid']['label'] = 'ID';
     $expected['mapping']['testdescription']['type'] = 'text';
@@ -388,7 +391,9 @@ public function testConfigSaveWithSchema() {
     $extension_path = drupal_get_path('module', 'config_schema_test');
     $install_storage = new FileStorage($extension_path . '/' . InstallStorage::CONFIG_INSTALL_DIRECTORY);
     $original_data = $install_storage->read('config_schema_test.ignore');
-    $this->assertIdentical($this->config('config_schema_test.ignore')->get(), $original_data);
+    $installed_data = $this->config('config_schema_test.ignore')->get();
+    unset($installed_data['_core']);
+    $this->assertIdentical($installed_data, $original_data);
   }
 
   /**
@@ -403,6 +408,7 @@ function testSchemaFallback() {
     $expected['definition_class'] = '\Drupal\Core\TypedData\MapDataDefinition';
     $expected['mapping']['langcode']['type'] = 'string';
     $expected['mapping']['langcode']['label'] = 'Language code';
+    $expected['mapping']['_core']['type'] = '_core_config_info';
     $expected['mapping']['testid']['type'] = 'string';
     $expected['mapping']['testid']['label'] = 'ID';
     $expected['mapping']['testdescription']['type'] = 'text';
diff --git a/core/modules/locale/src/LocaleConfigManager.php b/core/modules/locale/src/LocaleConfigManager.php
index de09fc3..d37c73b 100644
--- a/core/modules/locale/src/LocaleConfigManager.php
+++ b/core/modules/locale/src/LocaleConfigManager.php
@@ -493,7 +493,7 @@ public function getDefaultConfigLangcode($name) {
     // language list.
     $config_entity_type = $this->configManager->getEntityTypeIdByName($name);
     if (!$config_entity_type || $config_entity_type === 'configurable_language'
-      || !empty($this->configFactory->get($name)->get('default_config_hash'))
+      || !empty($this->configFactory->get($name)->get('_core.default_config_hash'))
     ) {
       $shipped = $this->defaultConfigStorage->read($name);
       if (!empty($shipped)) {
diff --git a/core/modules/locale/src/Tests/LocaleConfigManagerTest.php b/core/modules/locale/src/Tests/LocaleConfigManagerTest.php
index 3e3e697..193f4fa 100644
--- a/core/modules/locale/src/Tests/LocaleConfigManagerTest.php
+++ b/core/modules/locale/src/Tests/LocaleConfigManagerTest.php
@@ -26,6 +26,13 @@ class LocaleConfigManagerTest extends KernelTestBase {
   public static $modules = array('system', 'language', 'locale', 'locale_test', 'block');
 
   /**
+   * This test creates simple config on the fly breaking schema checking.
+   *
+   * @var bool
+   */
+  protected $strictConfigSchema = FALSE;
+
+  /**
    * Tests hasTranslation().
    */
   public function testHasTranslation() {
@@ -74,6 +81,10 @@ public function testGetDefaultConfigLangcode() {
     \Drupal::service('module_installer')->install(['locale_test_translate']);
     $this->assertEqual('en', \Drupal::service('locale.config_manager')->getDefaultConfigLangcode('locale_test_translate.settings'), 'After installing a module the locale config manager can get the shipped configuration langcode.');
 
+    $simple_config = \Drupal::configFactory()->getEditable('locale_test_translate.simple_config_extra');
+    $simple_config->set('foo', 'bar')->save();
+    $this->assertNull(\Drupal::service('locale.config_manager')->getDefaultConfigLangcode($simple_config->getName()), 'Simple config created through the API is not treated as shipped configuration.');
+
     $block = Block::create(array(
       'id' => 'test_default_config',
       'theme' => 'classy',
@@ -98,7 +109,7 @@ public function testGetDefaultConfigLangcode() {
     // The test_default_config block provided by the locale_test module will not
     // be installed because a block with the same ID already exists.
     $this->installConfig(['locale_test']);
-    $this->assertEqual(NULL, \Drupal::service('locale.config_manager')->getDefaultConfigLangcode('block.block.test_default_config'), 'The block.block.test_default_config is not shipped configuration.');
+    $this->assertNull(\Drupal::service('locale.config_manager')->getDefaultConfigLangcode('block.block.test_default_config'), 'The block.block.test_default_config is not shipped configuration.');
     // Delete the block so we can install the one provided by the locale_test
     // module.
     $block->delete();
@@ -111,7 +122,7 @@ public function testGetDefaultConfigLangcode() {
     $this->assertEqual('en', \Drupal::service('locale.config_manager')->getDefaultConfigLangcode('language.entity.fr'), 'The language.entity.fr is treated as shipped configuration because it is a configurable_language config entity and in the standard language list.');
     $custom_language = ConfigurableLanguage::createFromLangcode('custom');
     $custom_language->save();
-    $this->assertEqual(NULL, \Drupal::service('locale.config_manager')->getDefaultConfigLangcode('language.entity.custom'), 'The language.entity.custom is not shipped configuration because it is not in the standard language list.');
+    $this->assertNull(\Drupal::service('locale.config_manager')->getDefaultConfigLangcode('language.entity.custom'), 'The language.entity.custom is not shipped configuration because it is not in the standard language list.');
   }
 
 }
diff --git a/core/tests/Drupal/KernelTests/AssertConfigTrait.php b/core/tests/Drupal/KernelTests/AssertConfigTrait.php
index 8489ae7..203e85f 100644
--- a/core/tests/Drupal/KernelTests/AssertConfigTrait.php
+++ b/core/tests/Drupal/KernelTests/AssertConfigTrait.php
@@ -74,15 +74,15 @@ protected function assertConfigDiff(Diff $result, $config_name, array $skipped_c
           }
           break;
         case 'Drupal\Component\Diff\Engine\DiffOpAdd':
+          // The _core property does not exist in the default config.
+          if ($op->closing[0] === '_core:') {
+            continue;
+          }
           foreach ($op->closing as $closing) {
             // The UUIDs don't exist in the default config.
             if (strpos($closing, 'uuid: ') === 0)  {
               continue;
             }
-            // The UUIDs don't exist in the default config.
-            if (strpos($closing, 'default_config_hash: ') === 0)  {
-              continue;
-            }
             throw new \Exception($config_name . ': ' . var_export($op, TRUE));
           }
           break;
diff --git a/core/tests/Drupal/Tests/Core/Config/Entity/ConfigEntityTypeTest.php b/core/tests/Drupal/Tests/Core/Config/Entity/ConfigEntityTypeTest.php
index 44eae9a..8104efc 100644
--- a/core/tests/Drupal/Tests/Core/Config/Entity/ConfigEntityTypeTest.php
+++ b/core/tests/Drupal/Tests/Core/Config/Entity/ConfigEntityTypeTest.php
@@ -163,7 +163,7 @@ public function providerGetPropertiesToExport() {
         'status' => 'status',
         'dependencies' => 'dependencies',
         'third_party_settings' => 'third_party_settings',
-        'default_config_hash' => 'default_config_hash',
+        '_core' => '_core',
         'id' => 'id',
         'custom_property' => 'customProperty',
       ],