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..1112ed7 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.
@@ -40,6 +41,18 @@ class TypedConfigManager extends PluginManagerBase implements TypedConfigManager
   protected $definitions;
 
   /**
+   * The module handler to invoke the alter hook.
+   *
+   * @var \Drupal\Core\Extension\ModuleHandlerInterface
+   */
+  protected $moduleHandler;
+
+  /**
+   * @var string
+   */
+  protected $alterHook;
+
+  /**
    * Creates a new typed configuration manager.
    *
    * @param \Drupal\Core\Config\StorageInterface $configStorage
@@ -47,12 +60,26 @@ class TypedConfigManager extends PluginManagerBase implements TypedConfigManager
    * @param \Drupal\Core\Config\StorageInterface $schemaStorage
    *   The storage controller object to use for reading schema data
    */
-  public function __construct(StorageInterface $configStorage, StorageInterface $schemaStorage) {
+  public function __construct(StorageInterface $configStorage, StorageInterface $schemaStorage, ModuleHandlerInterface $module_handler) {
+    $this->alterInfo($module_handler, 'config_typed_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 $name
@@ -161,14 +188,18 @@ public function getDefinition($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;
   }