diff --git a/core/core.services.yml b/core/core.services.yml
index 7d9e831..39a6d6b 100644
--- a/core/core.services.yml
+++ b/core/core.services.yml
@@ -100,7 +100,7 @@ services:
     class: Drupal\Core\Config\InstallStorage
   config.typed:
     class: Drupal\Core\Config\TypedConfigManager
-    arguments: ['@config.storage', '@config.storage.schema']
+    arguments: ['@config.storage', '@config.storage.schema', '@module_handler']
   database:
     class: Drupal\Core\Database\Connection
     factory_class: Drupal\Core\Database\Database
diff --git a/core/lib/Drupal/Core/Config/TypedConfigManager.php b/core/lib/Drupal/Core/Config/TypedConfigManager.php
index 71aa0bc..96ecf66 100644
--- a/core/lib/Drupal/Core/Config/TypedConfigManager.php
+++ b/core/lib/Drupal/Core/Config/TypedConfigManager.php
@@ -12,6 +12,7 @@
 use Drupal\Component\Utility\NestedArray;
 use Drupal\Component\Utility\String;
 use Drupal\Core\Config\TypedConfigManagerInterface;
+use Drupal\Core\Extension\ModuleHandlerInterface;
 
 /**
  * Manages config type plugins.
@@ -40,19 +41,49 @@ class TypedConfigManager extends PluginManagerBase implements TypedConfigManager
   protected $definitions;
 
   /**
+   * The module handler to invoke the alter hook.
+   *
+   * @var \Drupal\Core\Extension\ModuleHandlerInterface
+   */
+  protected $moduleHandler;
+
+  /**
+   * Name of the alter hook if one should be invoked.
+   *
+   * @var string
+   */
+  protected $alterHook;
+
+  /**
    * Creates a new typed configuration manager.
    *
    * @param \Drupal\Core\Config\StorageInterface $configStorage
    *   The storage controller object to use for reading schema data
    * @param \Drupal\Core\Config\StorageInterface $schemaStorage
    *   The storage controller object to use for reading schema data
+   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
+   *  The module handler
    */
-  public function __construct(StorageInterface $configStorage, StorageInterface $schemaStorage) {
+  public function __construct(StorageInterface $configStorage, StorageInterface $schemaStorage, ModuleHandlerInterface $module_handler) {
+    $this->alterInfo($module_handler, 'config_type_info');
     $this->configStorage = $configStorage;
     $this->schemaStorage = $schemaStorage;
   }
 
   /**
+   * Initializes the alter hook.
+   *
+   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
+   *   The module handler to invoke the alter hook with.
+   * @param string $alter_hook
+   *   Name of the alter hook.
+   */
+  protected function alterInfo(ModuleHandlerInterface $module_handler, $alter_hook) {
+    $this->moduleHandler = $module_handler;
+    $this->alterHook = $alter_hook;
+  }
+
+  /**
    * Gets typed configuration data.
    *
    * @param string $name
@@ -161,14 +192,18 @@ public function getDefinition($base_plugin_id) {
    */
   public function getDefinitions() {
     if (!isset($this->definitions)) {
-      $this->definitions = array();
+      $definitions = array();
       foreach ($this->schemaStorage->listAll() as $name) {
         if ($schema = $this->schemaStorage->read($name)) {
           foreach ($schema as $type => $definition) {
-            $this->definitions[$type] = $definition;
+            $definitions[$type] = $definition;
           }
         }
       }
+      if ($this->alterHook) {
+        $this->moduleHandler->alter($this->alterHook, $definitions);
+      }
+      $this->definitions = $definitions;
     }
     return $this->definitions;
   }
diff --git a/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTest.php b/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTest.php
index 3b406b1..ba6452e 100644
--- a/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTest.php
@@ -242,4 +242,13 @@ function testSchemaData() {
     $this->assertEqual($site_slogan->getValue(), $new_slogan, 'Successfully updated the contained configuration data');
   }
 
+
+  /**
+   * Tests the alter hook for TypedConfig data types.
+   */
+  function testSchemaTypeAlter() {
+    $definitions = config_typed()->getDefinitions();
+    $this->assertTrue($definitions['label']['alter_hook_invoked']);
+  }
+
 }
diff --git a/core/modules/config/tests/config_test/config_test.module b/core/modules/config/tests/config_test/config_test.module
index b815610..0674f79 100644
--- a/core/modules/config/tests/config_test/config_test.module
+++ b/core/modules/config/tests/config_test/config_test.module
@@ -86,3 +86,10 @@ function config_test_entity_info_alter(&$entity_info) {
   unset($entity_info['config_test_no_status']['entity_keys']['status']);
   $entity_info['config_test_no_status']['config_prefix'] = 'config_test.no_status';
 }
+
+/**
+ * Implements hook_config_type_info_alter().
+ */
+function config_test_config_type_info_alter(&$info) {
+  $info['label']['alter_hook_invoked'] = TRUE;
+}
diff --git a/core/modules/locale/lib/Drupal/locale/LocaleConfigManager.php b/core/modules/locale/lib/Drupal/locale/LocaleConfigManager.php
index 9937d78..194934b 100644
--- a/core/modules/locale/lib/Drupal/locale/LocaleConfigManager.php
+++ b/core/modules/locale/lib/Drupal/locale/LocaleConfigManager.php
@@ -10,6 +10,7 @@
 use Drupal\Core\Language\Language;
 use Drupal\Core\Config\TypedConfigManager;
 use Drupal\Core\Config\StorageInterface;
+use Drupal\Core\Extension\ModuleHandlerInterface;
 
 /**
  * Manages localized configuration type plugins.
@@ -42,15 +43,17 @@ class LocaleConfigManager extends TypedConfigManager {
    *   The storage controller object to use for reading configuration data.
    * @param \Drupal\Core\Config\StorageInterface $schemaStorage
    *   The storage controller object to use for reading schema data.
+   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
+   *   The module handler
    * @param \Drupal\Core\Config\StorageInterface $installStorage
    *   The storage controller object to use for reading default configuration
    *   data.
    * @param \Drupal\locale\StringStorageInterface $localeStorage
    *   The locale storage to use for reading string translations.
    */
-  public function __construct(StorageInterface $configStorage, StorageInterface $schemaStorage, StorageInterface $installStorage, StringStorageInterface $localeStorage) {
+  public function __construct(StorageInterface $configStorage, StorageInterface $schemaStorage, ModuleHandlerInterface $module_handler, StorageInterface $installStorage, StringStorageInterface $localeStorage) {
     // Note we use the install storage for the parent constructor.
-    parent::__construct($configStorage, $schemaStorage);
+    parent::__construct($configStorage, $schemaStorage, $module_handler);
     $this->installStorage = $installStorage;
     $this->localeStorage = $localeStorage;
   }
diff --git a/core/modules/locale/locale.services.yml b/core/modules/locale/locale.services.yml
index f632704..0f7ee37 100644
--- a/core/modules/locale/locale.services.yml
+++ b/core/modules/locale/locale.services.yml
@@ -6,7 +6,7 @@ services:
     arguments: ['@language_manager', '@config.context']
   locale.config.typed:
     class: Drupal\locale\LocaleConfigManager
-    arguments: ['@config.storage', '@config.storage.schema', '@config.storage.installer', '@locale.storage']
+    arguments: ['@config.storage', '@config.storage.schema', '@module_handler', '@config.storage.installer', '@locale.storage']
   locale.storage:
     class: Drupal\locale\StringDatabaseStorage
     arguments: ['@database']
diff --git a/core/modules/system/system.api.php b/core/modules/system/system.api.php
index 0bde16e..6c93356 100644
--- a/core/modules/system/system.api.php
+++ b/core/modules/system/system.api.php
@@ -144,6 +144,16 @@ function hook_data_type_info_alter(&$data_types) {
 }
 
 /**
+ * Alter available data types for typed config.
+ *
+ * @param array $data_types
+ *   An array of data type information.
+ */
+function hook_config_type_info_alter(&$data_types) {
+  $data_types['label']['form_element_class'] = '\Drupal\mymodule\TypedConfig\Label';
+}
+
+/**
  * Declare queues holding items that need to be run periodically.
  *
  * While there can be only one hook_cron() process running at the same time,