diff -u b/core/modules/file/src/Tests/Migrate/d6/FileMigrationTestTrait.php b/core/modules/file/src/Tests/Migrate/d6/FileMigrationTestTrait.php
--- b/core/modules/file/src/Tests/Migrate/d6/FileMigrationTestTrait.php
+++ b/core/modules/file/src/Tests/Migrate/d6/FileMigrationTestTrait.php
@@ -1,5 +1,10 @@
 <?php
 
+/**
+ * @file
+ * Contains \Drupal\file\Tests\Migrate\d6\FileMigrationTestTrait.
+ */
+
 namespace Drupal\file\Tests\Migrate\d6;
 
 /**
diff -u b/core/modules/migrate/src/Plugin/MigrationPluginManager.php b/core/modules/migrate/src/Plugin/MigrationPluginManager.php
--- b/core/modules/migrate/src/Plugin/MigrationPluginManager.php
+++ b/core/modules/migrate/src/Plugin/MigrationPluginManager.php
@@ -5,15 +5,14 @@
  * Contains \Drupal\migrate\Plugin\MigrationPluginManager.
  */
 
-
 namespace Drupal\migrate\Plugin;
 
-
 use Drupal\Core\Cache\CacheBackendInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Language\LanguageManagerInterface;
 use Drupal\Core\Plugin\DefaultPluginManager;
 use Drupal\Core\Plugin\Discovery\ContainerDerivativeDiscoveryDecorator;
+use Drupal\Core\Plugin\Discovery\YamlDirectoryDiscovery;
 use Drupal\Core\Plugin\Factory\ContainerFactory;
 
 /**
@@ -66,7 +65,11 @@
    */
   protected function getDiscovery() {
     if (!isset($this->discovery)) {
-      $yaml_discovery = new MigrationYamlDiscovery($this->moduleHandler->getModuleDirectories());
+      $directories = array_map(function($directory) {
+        return [$directory . '/migration_templates', $directory . '/migrations'];
+      }, $this->moduleHandler->getModuleDirectories());
+
+      $yaml_discovery = new YamlDirectoryDiscovery($directories, 'migrate');
       $this->discovery = new ContainerDerivativeDiscoveryDecorator($yaml_discovery);
     }
     return $this->discovery;
reverted:
--- b/core/modules/migrate/src/Plugin/MigrationYamlDiscovery.php
+++ /dev/null
@@ -1,96 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains \Drupal\migrate\Plugin\MigrationYamlDiscovery.
- */
-
-
-namespace Drupal\migrate\Plugin;
-
-use Drupal\Component\Discovery\DiscoverableInterface;
-use Drupal\Component\FileCache\FileCacheFactory;
-use Drupal\Component\Serialization\Yaml;
-use Drupal\Core\Plugin\Discovery\YamlDiscovery;
-
-/**
- * One migration per YAML file discovery.
- *
- * Migrations should be in MODULENAME/migrations. Also, for backwards
- * compatibility, migrations in MODULENAME/migration_templates are also
- * discovered.
- */
-class MigrationYamlDiscovery extends YamlDiscovery implements DiscoverableInterface {
-
-  /**
-   * @var array
-   */
-  protected $directories;
-
-  /**
-   * Constructs a MigrationYamlDiscovery object.
-   *
-   * @param array $directories
-   *   An array of directories to scan, keyed by the provider.
-   */
-  public function __construct(array $directories) {
-    $this->directories = $directories;
-    $this->discovery = $this;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function findAll() {
-    $all = [];
-
-    $provider_by_files = $this->findFiles();
-
-    $file_cache = FileCacheFactory::get('yaml_discovery:migration');
-
-    // Try to load from the file cache first.
-    foreach ($file_cache->getMultiple(array_keys($provider_by_files)) as $file => $data) {
-      $all[$provider_by_files[$file]][$data['id']] = $data;
-      unset($provider_by_files[$file]);
-    }
-
-    // If there are files left that were not returned from the cache, load and
-    // parse them now.
-    if ($provider_by_files) {
-      foreach ($provider_by_files as $file => $provider) {
-        // If a file is empty or its contents are commented out, return an empty
-        // array instead of NULL for type consistency.
-        $contents = Yaml::decode(file_get_contents($file)) ?: [];
-        if (!isset($contents['id'])) {
-          list($contents['id']) = explode('.', basename($file), 2);
-        }
-        $all[$provider][$contents['id']] = $contents;
-        $file_cache->set($file, $contents);
-      }
-    }
-
-    return $all;
-  }
-
-  /**
-   * Finds the migration files.
-   *
-   * @return array
-   *   Keys are the filenames, values are the provider.
-   */
-  protected function findFiles() {
-    $files = [];
-    foreach ($this->directories as $provider => $directory) {
-      foreach (['migration_templates', 'migrations'] as $subdirectory) {
-        $full_path = "$directory/$subdirectory";
-        if (is_dir($full_path)) {
-          foreach (glob("$full_path/*.yml") as $filename) {
-            $files[$filename] = $provider;
-          }
-        }
-      }
-    }
-    return $files;
-  }
-
-}
diff -u b/core/modules/migrate_drupal/src/Plugin/migrate/D6NodeDeriver.php b/core/modules/migrate_drupal/src/Plugin/migrate/D6NodeDeriver.php
--- b/core/modules/migrate_drupal/src/Plugin/migrate/D6NodeDeriver.php
+++ b/core/modules/migrate_drupal/src/Plugin/migrate/D6NodeDeriver.php
@@ -5,7 +5,6 @@
  * Contains \Drupal\migrate_drupal\Plugin\migrate\D6NodeDeriver.
  */
 
-
 namespace Drupal\migrate_drupal\Plugin\migrate;
 
 use Drupal\Component\Plugin\Derivative\DeriverBase;
diff -u b/core/modules/migrate_drupal/src/Plugin/migrate/D7NodeDeriver.php b/core/modules/migrate_drupal/src/Plugin/migrate/D7NodeDeriver.php
--- b/core/modules/migrate_drupal/src/Plugin/migrate/D7NodeDeriver.php
+++ b/core/modules/migrate_drupal/src/Plugin/migrate/D7NodeDeriver.php
@@ -5,7 +5,6 @@
  * Contains \Drupal\migrate_drupal\Plugin\migrate\D7NodeDeriver.
  */
 
-
 namespace Drupal\migrate_drupal\Plugin\migrate;
 
 use Drupal\Component\Plugin\Derivative\DeriverBase;
diff -u b/core/modules/user/src/Plugin/migrate/ProfileValues.php b/core/modules/user/src/Plugin/migrate/ProfileValues.php
--- b/core/modules/user/src/Plugin/migrate/ProfileValues.php
+++ b/core/modules/user/src/Plugin/migrate/ProfileValues.php
@@ -5,7 +5,6 @@
  * Contains \Drupal\user\Plugin\migrate\ProfileValues.
  */
 
-
 namespace Drupal\user\Plugin\migrate;
 
 use Drupal\migrate\Plugin\Migration;