diff -u b/migrate_plus.module b/migrate_plus.module
--- b/migrate_plus.module
+++ b/migrate_plus.module
@@ -5,16 +5,8 @@
  * Provides tools and enhancements for implementing and managing migrations.
  */
 
-/**
- * Implements hook_entity_type_alter().
- */
-function migrate_plus_entity_type_alter(array &$entity_types) {
-  // Substitute our own classes to provide enhanced functionality to the
-  // migration entity type.
-  /** @var \Drupal\Core\Config\Entity\ConfigEntityType[] $entity_types */
-  $entity_types['migration']
-    ->setHandlerClass('storage', 'Drupal\migrate_plus\MigrationStorage');
-}
+use Drupal\migrate\Entity\MigrationInterface;
+use Drupal\migrate_plus\Entity\MigrationGroupInterface;
 
 /**
  * Implements hook_config_schema_info_alter().
@@ -30,0 +23,36 @@
+
+/**
+ * Implements hook_ENTITY_TYPE_load().
+ */
+function migrate_plus_migration_load($migrations) {
+  /** @var MigrationInterface $migration */
+  foreach ($migrations as $migration) {
+    // If we are pointing to a valid group, merge its properties into ours.
+    if (isset($migration->migration_group)) {
+      /** @var MigrationGroupInterface $group */
+      $group = entity_load('migration_group', $migration->migration_group);
+      if ($group) {
+        $shared_configuration = $group->get('shared_configuration');
+        if ($shared_configuration) {
+          foreach ($shared_configuration as $key => $group_value) {
+            $migration_value = $migration->get($key);
+            // Where both the migration and the group provide arrays,
+            // replace recursively (so each key collision is resolved in favor
+            // of the migration).
+            if (is_array($migration_value) && is_array($group_value)) {
+              $merged_values = array_replace_recursive($group_value, $migration_value);
+              $migration->set($key, $merged_values);
+            }
+            // Where the group provides a value the migration doesn't, use
+            // the group value.
+            elseif (is_null($migration_value)) {
+              $migration->set($key, $group_value);
+            }
+            // Otherwise, the existing migration value overrides the group
+            // value.
+          }
+        }
+      }
+    }
+  }
+}
reverted:
--- b/src/MigrationStorage.php
+++ /dev/null
@@ -1,103 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains \Drupal\migrate_plus\MigrateStorage.
- */
-
-namespace Drupal\migrate_plus;
-
-use Drupal\Component\Uuid\UuidInterface;
-use Drupal\Core\Config\ConfigFactoryInterface;
-use Drupal\Core\Entity\EntityTypeInterface;
-use Drupal\Core\Entity\EntityStorageInterface;
-use Drupal\Core\Language\LanguageManagerInterface;
-use Drupal\migrate\Entity\MigrationInterface;
-use Drupal\migrate_plus\Entity\MigrationGroupInterface;
-use Drupal\migrate\MigrationStorage as BaseMigrationStorage;
-use Symfony\Component\DependencyInjection\ContainerInterface;
-
-/**
- * Storage for migration entities.
- */
-class MigrationStorage extends BaseMigrationStorage {
-
-  /**
-   * The migration group storage.
-   *
-   * @var \Drupal\Core\Entity\EntityInterface
-   */
-  protected $migrationGroupStorage;
-
-  /**
-   * Constructs a MigrationStorage object.
-   *
-   * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
-   *   The entity type definition.
-   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
-   *   The config factory service.
-   * @param \Drupal\Component\Uuid\UuidInterface $uuid_service
-   *   The UUID service.
-   * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
-   *   The language manager.
-   * @param \Drupal\Core\Entity\EntityStorageInterface $migration_group_storage
-   *   The migration group storage.
-   */
-  public function __construct(EntityTypeInterface $entity_type, ConfigFactoryInterface $config_factory, UuidInterface $uuid_service, LanguageManagerInterface $language_manager, EntityStorageInterface $migration_group_storage) {
-    parent::__construct($entity_type, $config_factory, $uuid_service, $language_manager);
-    $this->migrationGroupStorage = $migration_group_storage;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public static function createInstance(ContainerInterface $container, EntityTypeInterface $entity_type) {
-    return new static(
-      $entity_type,
-      $container->get('config.factory'),
-      $container->get('uuid'),
-      $container->get('language_manager'),
-      $container->get('entity.manager')->getStorage('migration_group')
-    );
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  protected function doLoadMultiple(array $ids = NULL) {
-    $migrations = parent::doLoadMultiple($ids);
-
-    /** @var MigrationInterface $migration */
-    foreach ($migrations as $migration) {
-      // If we are pointing to a valid group, merge its properties into ours.
-      if (isset($migration->migration_group)) {
-        /** @var MigrationGroupInterface $group */
-        $group = $this->migrationGroupStorage->load($migration->migration_group);
-        if ($group) {
-          $shared_configuration = $group->get('shared_configuration');
-          if ($shared_configuration) {
-            foreach ($shared_configuration as $key => $group_value) {
-              $migration_value = $migration->get($key);
-              // Where both the migration and the group provide arrays,
-              // replace recursively (so each key collision is resolved in favor
-              // of the migration).
-              if (is_array($migration_value) && is_array($group_value)) {
-                $merged_values = array_replace_recursive($group_value, $migration_value);
-                $migration->set($key, $merged_values);
-              }
-              // Where the group provides a value the migration doesn't, use
-              // the group value.
-              elseif (is_null($migration_value)) {
-                $migration->set($key, $group_value);
-              }
-              // Otherwise, the existing migration value overrides the group
-              // value.
-            }
-          }
-        }
-      }
-    }
-    return $migrations;
-  }
-
-}