diff --git a/core/lib/Drupal/Component/Plugin/Discovery/StaticDiscovery.php b/core/lib/Drupal/Component/Plugin/Discovery/StaticDiscovery.php
index de74fb5..c406d28 100644
--- a/core/lib/Drupal/Component/Plugin/Discovery/StaticDiscovery.php
+++ b/core/lib/Drupal/Component/Plugin/Discovery/StaticDiscovery.php
@@ -37,7 +37,7 @@ public function getDefinitions() {
   /**
    * Sets a plugin definition.
    */
-  public function setDefinition($plugin, array $definition) {
+  public function setDefinition($plugin, $definition) {
     $this->definitions[$plugin] = $definition;
   }
 
diff --git a/core/lib/Drupal/Core/Entity/EntityManager.php b/core/lib/Drupal/Core/Entity/EntityManager.php
index 3fe2c54..428c83b 100644
--- a/core/lib/Drupal/Core/Entity/EntityManager.php
+++ b/core/lib/Drupal/Core/Entity/EntityManager.php
@@ -9,19 +9,14 @@
 
 use Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException;
 use Drupal\Component\Plugin\Exception\PluginNotFoundException;
-use Drupal\Component\Plugin\PluginManagerBase;
-use Drupal\Component\Utility\NestedArray;
 use Drupal\Component\Utility\String;
 use Drupal\Core\Field\FieldDefinition;
 use Drupal\Core\Cache\Cache;
 use Drupal\Core\Cache\CacheBackendInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
-use Drupal\Core\Language\LanguageManager;
+use Drupal\Core\Language\LanguageManagerInterface;
 use Drupal\Core\Language\Language;
-use Drupal\Core\Plugin\Discovery\AlterDecorator;
-use Drupal\Core\Plugin\Discovery\CacheDecorator;
-use Drupal\Core\Plugin\Discovery\AnnotatedClassDiscovery;
-use Drupal\Core\Plugin\Discovery\InfoHookDecorator;
+use Drupal\Core\Plugin\DefaultPluginManager;
 use Drupal\Core\StringTranslation\StringTranslationTrait;
 use Drupal\Core\StringTranslation\TranslationInterface;
 use Drupal\Core\TypedData\TranslatableInterface;
@@ -42,7 +37,7 @@
  * @see \Drupal\Core\Entity\EntityTypeInterface
  * @see hook_entity_type_alter()
  */
-class EntityManager extends PluginManagerBase implements EntityManagerInterface, ContainerAwareInterface  {
+class EntityManager extends DefaultPluginManager implements EntityManagerInterface, ContainerAwareInterface {
 
   use ContainerAwareTrait;
   use StringTranslationTrait;
@@ -62,27 +57,6 @@ class EntityManager extends PluginManagerBase implements EntityManagerInterface,
   protected $controllers = array();
 
   /**
-   * The module handler.
-   *
-   * @var \Drupal\Core\Extension\ModuleHandlerInterface
-   */
-  protected $moduleHandler;
-
-  /**
-   * The cache backend to use.
-   *
-   * @var \Drupal\Core\Cache\CacheBackendInterface
-   */
-  protected $cache;
-
-  /**
-   * The language manager.
-   *
-   * @var \Drupal\Core\Language\LanguageManager
-   */
-  protected $languageManager;
-
-  /**
    * Static cache of base field definitions.
    *
    * @var array
@@ -107,15 +81,6 @@ class EntityManager extends PluginManagerBase implements EntityManagerInterface,
   protected $fieldStorageDefinitions;
 
   /**
-   * The root paths.
-   *
-   * @see self::__construct().
-   *
-   * @var \Traversable
-   */
-  protected $namespaces;
-
-  /**
    * The string translationManager.
    *
    * @var \Drupal\Core\StringTranslation\TranslationInterface
@@ -156,25 +121,18 @@ class EntityManager extends PluginManagerBase implements EntityManagerInterface,
    *   The module handler.
    * @param \Drupal\Core\Cache\CacheBackendInterface $cache
    *   The cache backend to use.
-   * @param \Drupal\Core\Language\LanguageManager $language_manager
+   * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
    *   The language manager.
    * @param \Drupal\Core\StringTranslation\TranslationInterface $translation_manager
    *   The string translationManager.
    */
-  public function __construct(\Traversable $namespaces, ModuleHandlerInterface $module_handler, CacheBackendInterface $cache, LanguageManager $language_manager, TranslationInterface $translation_manager) {
-    // Allow the plugin definition to be altered by hook_entity_type_alter().
+  public function __construct(\Traversable $namespaces, ModuleHandlerInterface $module_handler, CacheBackendInterface $cache, LanguageManagerInterface $language_manager, TranslationInterface $translation_manager) {
+    parent::__construct('Entity', $namespaces, $module_handler, 'Drupal\Core\Entity\Annotation\EntityType');
+
+    $this->setCacheBackend($cache, $language_manager, 'entity_type:', array('entity_types' => TRUE));
+    $this->alterInfo('entity_type');
 
-    $this->moduleHandler = $module_handler;
-    $this->cache = $cache;
-    $this->languageManager = $language_manager;
-    $this->namespaces = $namespaces;
     $this->translationManager = $translation_manager;
-
-    $this->discovery = new AnnotatedClassDiscovery('Entity', $namespaces, 'Drupal\Core\Entity\Annotation\EntityType');
-    $this->discovery = new InfoHookDecorator($this->discovery, 'entity_type_build');
-    $this->discovery = new AlterDecorator($this->discovery, 'entity_type');
-    $this->discovery = new CacheDecorator($this->discovery, 'entity_type:' . $this->languageManager->getCurrentLanguage()->id, 'discovery', Cache::PERMANENT, array('entity_types' => TRUE));
-
   }
 
   /**
@@ -191,6 +149,27 @@ public function clearCachedDefinitions() {
   /**
    * {@inheritdoc}
    */
+  protected function findDefinitions() {
+    $definitions = $this->discovery->getDefinitions();
+
+    // Directly call the hook implementations to pass the definitions to them
+    // by reference, so new entity types can be added.
+    foreach ($this->moduleHandler->getImplementations('entity_type_build') as $module) {
+      $function = $module . '_' . 'entity_type_build';
+      $function($definitions);
+    }
+    foreach ($definitions as $plugin_id => $definition) {
+      $this->processDefinition($definition, $plugin_id);
+    }
+    if ($this->alterHook) {
+      $this->moduleHandler->alter($this->alterHook, $definitions);
+    }
+    return $definitions;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public function getDefinition($entity_type_id, $exception_on_invalid = FALSE) {
     if (($entity_type = parent::getDefinition($entity_type_id)) && class_exists($entity_type->getClass())) {
       return $entity_type;
@@ -330,13 +309,13 @@ public function getBaseFieldDefinitions($entity_type_id) {
     if (!isset($this->baseFieldDefinitions[$entity_type_id])) {
       // Not prepared, try to load from cache.
       $cid = 'entity_base_field_definitions:' . $entity_type_id . ':' . $this->languageManager->getCurrentLanguage()->id;
-      if ($cache = $this->cache->get($cid)) {
+      if ($cache = $this->cacheBackend->get($cid)) {
         $this->baseFieldDefinitions[$entity_type_id] = $cache->data;
       }
       else {
         // Rebuild the definitions and put it into the cache.
         $this->baseFieldDefinitions[$entity_type_id] = $this->buildBaseFieldDefinitions($entity_type_id);
-        $this->cache->set($cid, $this->baseFieldDefinitions[$entity_type_id], Cache::PERMANENT, array('entity_types' => TRUE, 'entity_field_info' => TRUE));
+        $this->cacheBackend->set($cid, $this->baseFieldDefinitions[$entity_type_id], Cache::PERMANENT, array('entity_types' => TRUE, 'entity_field_info' => TRUE));
        }
      }
     return $this->baseFieldDefinitions[$entity_type_id];
@@ -426,13 +405,13 @@ public function getFieldDefinitions($entity_type_id, $bundle) {
       $base_field_definitions = $this->getBaseFieldDefinitions($entity_type_id);
       // Not prepared, try to load from cache.
       $cid = 'entity_bundle_field_definitions:' . $entity_type_id . ':' . $bundle . ':' . $this->languageManager->getCurrentLanguage()->id;
-      if ($cache = $this->cache->get($cid)) {
+      if ($cache = $this->cacheBackend->get($cid)) {
         $bundle_field_definitions = $cache->data;
       }
       else {
         // Rebuild the definitions and put it into the cache.
         $bundle_field_definitions = $this->buildBundleFieldDefinitions($entity_type_id, $bundle, $base_field_definitions);
-        $this->cache->set($cid, $bundle_field_definitions, Cache::PERMANENT, array('entity_types' => TRUE, 'entity_field_info' => TRUE));
+        $this->cacheBackend->set($cid, $bundle_field_definitions, Cache::PERMANENT, array('entity_types' => TRUE, 'entity_field_info' => TRUE));
       }
       // Field definitions consist of the bundle specific overrides and the
       // base fields, merge them together. Use array_replace() to replace base
@@ -518,13 +497,13 @@ public function getFieldStorageDefinitions($entity_type_id) {
       }
       // Not prepared, try to load from cache.
       $cid = 'entity_field_storage_definitions:' . $entity_type_id . ':' . $this->languageManager->getCurrentLanguage()->id;
-      if ($cache = $this->cache->get($cid)) {
+      if ($cache = $this->cacheBackend->get($cid)) {
         $field_storage_definitions = $cache->data;
       }
       else {
         // Rebuild the definitions and put it into the cache.
         $field_storage_definitions = $this->buildFieldStorageDefinitions($entity_type_id);
-        $this->cache->set($cid, $field_storage_definitions, Cache::PERMANENT, array('entity_types' => TRUE, 'entity_field_info' => TRUE));
+        $this->cacheBackend->set($cid, $field_storage_definitions, Cache::PERMANENT, array('entity_types' => TRUE, 'entity_field_info' => TRUE));
       }
       $this->fieldStorageDefinitions[$entity_type_id] += $field_storage_definitions;
     }
@@ -538,7 +517,7 @@ public function getFieldMap() {
     if (!$this->fieldMap) {
       // Not prepared, try to load from cache.
       $cid = 'entity_field_map';
-      if ($cache = $this->cache->get($cid)) {
+      if ($cache = $this->cacheBackend->get($cid)) {
         $this->fieldMap = $cache->data;
       }
       else {
@@ -554,7 +533,7 @@ public function getFieldMap() {
           }
         }
 
-        $this->cache->set($cid, $this->fieldMap, Cache::PERMANENT, array('entity_types' => TRUE, 'entity_field_info' => TRUE));
+        $this->cacheBackend->set($cid, $this->fieldMap, Cache::PERMANENT, array('entity_types' => TRUE, 'entity_field_info' => TRUE));
       }
     }
     return $this->fieldMap;
@@ -622,7 +601,7 @@ public function getBundleInfo($entity_type) {
   public function getAllBundleInfo() {
     if (!isset($this->bundleInfo)) {
       $langcode = $this->languageManager->getCurrentLanguage()->id;
-      if ($cache = $this->cache->get("entity_bundle_info:$langcode")) {
+      if ($cache = $this->cacheBackend->get("entity_bundle_info:$langcode")) {
         $this->bundleInfo = $cache->data;
       }
       else {
@@ -643,7 +622,7 @@ public function getAllBundleInfo() {
           }
         }
         $this->moduleHandler->alter('entity_bundle_info', $this->bundleInfo);
-        $this->cache->set("entity_bundle_info:$langcode", $this->bundleInfo, Cache::PERMANENT, array('entity_types' => TRUE));
+        $this->cacheBackend->set("entity_bundle_info:$langcode", $this->bundleInfo, Cache::PERMANENT, array('entity_types' => TRUE));
       }
     }
 
@@ -663,7 +642,7 @@ public function getExtraFields($entity_type_id, $bundle) {
     // hook_entity_extra_field_info_alter() might contain t() calls, we cache
     // per language.
     $cache_id = 'entity_bundle_extra_fields:' . $entity_type_id . ':' . $bundle . ':' . $this->languageManager->getCurrentLanguage()->id;
-    $cached = $this->cache->get($cache_id);
+    $cached = $this->cacheBackend->get($cache_id);
     if ($cached) {
       $this->extraFields[$entity_type_id][$bundle] = $cached->data;
       return $this->extraFields[$entity_type_id][$bundle];
@@ -679,7 +658,7 @@ public function getExtraFields($entity_type_id, $bundle) {
 
     // Store in the 'static' and persistent caches.
     $this->extraFields[$entity_type_id][$bundle] = $info;
-    $this->cache->set($cache_id, $info, Cache::PERMANENT, array(
+    $this->cacheBackend->set($cache_id, $info, Cache::PERMANENT, array(
       'entity_field_info' => TRUE,
     ));
 
@@ -790,7 +769,7 @@ protected function getAllDisplayModesByEntityType($display_type) {
     if (!isset($this->displayModeInfo[$display_type])) {
       $key = 'entity_' . $display_type . '_info';
       $langcode = $this->languageManager->getCurrentLanguage(Language::TYPE_INTERFACE)->id;
-      if ($cache = $this->cache->get("$key:$langcode")) {
+      if ($cache = $this->cacheBackend->get("$key:$langcode")) {
         $this->displayModeInfo[$display_type] = $cache->data;
       }
       else {
@@ -800,7 +779,7 @@ protected function getAllDisplayModesByEntityType($display_type) {
           $this->displayModeInfo[$display_type][$display_mode_entity_type][$display_mode_name] = (array) $display_mode;
         }
         $this->moduleHandler->alter($key, $this->displayModeInfo[$display_type]);
-        $this->cache->set("$key:$langcode", $this->displayModeInfo[$display_type], CacheBackendInterface::CACHE_PERMANENT, array('entity_types' => TRUE));
+        $this->cacheBackend->set("$key:$langcode", $this->displayModeInfo[$display_type], CacheBackendInterface::CACHE_PERMANENT, array('entity_types' => TRUE));
       }
     }
 
diff --git a/core/lib/Drupal/Core/Plugin/DefaultPluginManager.php b/core/lib/Drupal/Core/Plugin/DefaultPluginManager.php
index e9c4ce9..1f8a425 100644
--- a/core/lib/Drupal/Core/Plugin/DefaultPluginManager.php
+++ b/core/lib/Drupal/Core/Plugin/DefaultPluginManager.php
@@ -270,6 +270,11 @@ protected function findDefinitions() {
     // If this plugin was provided by a module that does not exist, remove the
     // plugin definition.
     foreach ($definitions as $plugin_id => $plugin_definition) {
+      // If the plugin definition is an object, attempt to convert it to an
+      // array, if that is not possible, skip further processing.
+      if (is_object($plugin_definition) && !($plugin_definition = (array) $plugin_definition)) {
+        continue;
+      }
       if (isset($plugin_definition['provider']) && !in_array($plugin_definition['provider'], array('Core', 'Component')) && !$this->moduleHandler->moduleExists($plugin_definition['provider'])) {
         unset($definitions[$plugin_id]);
       }
diff --git a/core/tests/Drupal/Tests/Core/Entity/EntityManagerTest.php b/core/tests/Drupal/Tests/Core/Entity/EntityManagerTest.php
index 100ad29..7630eb0 100644
--- a/core/tests/Drupal/Tests/Core/Entity/EntityManagerTest.php
+++ b/core/tests/Drupal/Tests/Core/Entity/EntityManagerTest.php
@@ -5,7 +5,7 @@
  * Contains \Drupal\Tests\Core\Entity\EntityManagerTest.
  */
 
-namespace Drupal\Tests\Core\Entity;
+namespace Drupal\Tests\Core\Entity {
 
 use Drupal\Component\Plugin\Discovery\DiscoveryInterface;
 use Drupal\Core\DependencyInjection\ContainerBuilder;
@@ -80,13 +80,6 @@ class EntityManagerTest extends UnitTestCase {
   protected $translationManager;
 
   /**
-   * The form builder.
-   *
-   * @var \Drupal\Core\Form\FormBuilderInterface|\PHPUnit_Framework_MockObject_MockObject
-   */
-  protected $formBuilder;
-
-  /**
    * {@inheritdoc}
    */
   public static function getInfo() {
@@ -111,20 +104,19 @@ protected function setUp() {
 
     $this->cache = $this->getMock('Drupal\Core\Cache\CacheBackendInterface');
 
-    $this->languageManager = $this->getMockBuilder('Drupal\Core\Language\LanguageManager')
-      ->disableOriginalConstructor()
-      ->getMock();
+    $this->languageManager = $this->getMock('Drupal\Core\Language\LanguageManagerInterface');
     $this->languageManager->expects($this->any())
       ->method('getCurrentLanguage')
       ->will($this->returnValue((object) array('id' => 'en')));
+    $this->languageManager->expects($this->any())
+      ->method('getLanguages')
+      ->will($this->returnValue(array('en' => (object) array('id' => 'en'))));
 
     $this->translationManager = $this->getStringTranslationStub();
 
-    $this->formBuilder = $this->getMock('Drupal\Core\Form\FormBuilderInterface');
-
     $this->container = $this->getContainerWithCacheBins($this->cache);
 
-    $this->discovery = $this->getMock('Drupal\Component\Plugin\Discovery\CachedDiscoveryInterface');
+    $this->discovery = $this->getMock('Drupal\Component\Plugin\Discovery\DiscoveryInterface');
   }
 
   /**
@@ -149,7 +141,7 @@ protected function setUpEntityManager($definitions = array()) {
       ->method('getDefinitions')
       ->will($this->returnValue($definitions));
 
-    $this->entityManager = new TestEntityManager(new \ArrayObject(), $this->moduleHandler, $this->cache, $this->languageManager, $this->translationManager, $this->formBuilder);
+    $this->entityManager = new TestEntityManager(new \ArrayObject(), $this->moduleHandler, $this->cache, $this->languageManager, $this->translationManager);
     $this->entityManager->setContainer($this->container);
     $this->entityManager->setDiscovery($this->discovery);
   }
@@ -162,8 +154,9 @@ protected function setUpEntityManager($definitions = array()) {
    */
   public function testClearCachedDefinitions() {
     $this->setUpEntityManager();
-    $this->discovery->expects($this->once())
-      ->method('clearCachedDefinitions');
+    $this->cache->expects($this->once())
+      ->method('deleteTags')
+      ->with(array('entity_types' => TRUE));
 
     $this->entityManager->clearCachedDefinitions();
   }
@@ -491,15 +484,13 @@ public function testGetFieldStorageDefinitions() {
       ->method('getName')
       ->will($this->returnValue('field_storage'));
 
-    $this->moduleHandler->expects($this->at(0))
+    $this->moduleHandler->expects($this->any())
       ->method('getImplementations')
-      ->with('entity_base_field_info')
-      ->will($this->returnValue(array()));
-
-    $this->moduleHandler->expects($this->at(2))
-      ->method('getImplementations')
-      ->with('entity_field_storage_info')
-      ->will($this->returnValue(array('example_module')));
+      ->will($this->returnValueMap(array(
+        array('entity_type_build', array()),
+        array('entity_base_field_info', array()),
+        array('entity_field_storage_info', array('example_module')),
+      )));
 
     $this->moduleHandler->expects($this->any())
       ->method('invoke')
@@ -527,9 +518,17 @@ public function testGetBaseFieldDefinitionsWithCaching() {
       ->method('get')
       ->with('entity_base_field_definitions:test_entity_type:en', FALSE)
       ->will($this->returnValue(FALSE));
-    $this->cache->expects($this->once())
-      ->method('set');
+    $this->cache->expects($this->at(1))
+      ->method('get')
+      ->with('entity_type::en', FALSE)
+      ->will($this->returnValue(FALSE));
     $this->cache->expects($this->at(2))
+      ->method('set')
+      ->with('entity_type::en');
+    $this->cache->expects($this->at(3))
+      ->method('set')
+      ->with('entity_base_field_definitions:test_entity_type:en');
+    $this->cache->expects($this->at(4))
       ->method('get')
       ->with('entity_base_field_definitions:test_entity_type:en', FALSE)
       ->will($this->returnValue((object) array('data' => $expected)));
@@ -558,12 +557,18 @@ public function testGetFieldDefinitionsWithCaching() {
       ->with('entity_bundle_field_definitions:test_entity_type:test_bundle:en', FALSE)
       ->will($this->returnValue(FALSE));
     $this->cache->expects($this->at(2))
-      ->method('set');
+      ->method('get')
+      ->with('entity_type::en', FALSE)
+      ->will($this->returnValue(FALSE));
     $this->cache->expects($this->at(3))
+      ->method('set');
+    $this->cache->expects($this->at(4))
+      ->method('set');
+    $this->cache->expects($this->at(5))
       ->method('get')
       ->with('entity_base_field_definitions:test_entity_type:en', FALSE)
       ->will($this->returnValue((object) array('data' => $expected)));
-    $this->cache->expects($this->at(4))
+    $this->cache->expects($this->at(6))
       ->method('get')
       ->with('entity_bundle_field_definitions:test_entity_type:test_bundle:en', FALSE)
       ->will($this->returnValue((object) array('data' => $expected)));
@@ -587,8 +592,10 @@ public function testGetFieldStorageDefinitionsWithCaching() {
 
     $this->moduleHandler->expects($this->any())
       ->method('getImplementations')
-      ->with('entity_field_storage_info')
-      ->will($this->returnValue(array('example_module')));
+      ->will($this->returnValueMap(array(
+        array('entity_field_storage_info', array('example_module')),
+        array('entity_type_build', array())
+      )));
 
     $this->moduleHandler->expects($this->once())
       ->method('invoke')
@@ -609,12 +616,20 @@ public function testGetFieldStorageDefinitionsWithCaching() {
       ->with('entity_field_storage_definitions:test_entity_type:en', FALSE)
       ->will($this->returnValue(FALSE));
     $this->cache->expects($this->at(2))
-      ->method('set');
+      ->method('get')
+      ->with('entity_type::en', FALSE)
+      ->will($this->returnValue(FALSE));
     $this->cache->expects($this->at(3))
+      ->method('set')
+      ->with('entity_type::en');
+    $this->cache->expects($this->at(4))
+      ->method('set')
+      ->with('entity_field_storage_definitions:test_entity_type:en');
+    $this->cache->expects($this->at(5))
       ->method('get')
       ->with('entity_base_field_definitions:test_entity_type:en', FALSE)
       ->will($this->returnValue((object) array('data' => array('id' => $expected['id']))));
-    $this->cache->expects($this->at(4))
+    $this->cache->expects($this->at(6))
       ->method('get')
       ->with('entity_field_storage_definitions:test_entity_type:en', FALSE)
       ->will($this->returnValue((object) array('data' => $expected)));
@@ -809,14 +824,27 @@ public function testGetAllBundleInfo() {
       'apple' => $apple,
       'banana' => $banana,
     ));
+    $this->cache->expects($this->at(0))
+      ->method('get')
+      ->with("entity_bundle_info:en", FALSE)
+      ->will($this->returnValue(FALSE));
     $this->cache->expects($this->at(1))
       ->method('get')
+      ->with("entity_type::en", FALSE)
       ->will($this->returnValue(FALSE));
     $this->cache->expects($this->at(2))
+      ->method('set')
+      ->with("entity_type::en");
+    $this->cache->expects($this->at(3))
+      ->method('set')
+      ->with("entity_bundle_info:en");
+    $this->cache->expects($this->at(4))
+      ->method('deleteTags')
+      ->with(array('entity_types' => TRUE));
+    $this->cache->expects($this->at(5))
       ->method('get')
+      ->with("entity_bundle_info:en", FALSE)
       ->will($this->returnValue((object) array('data' => 'cached data')));
-    $this->cache->expects($this->once())
-      ->method('set');
 
     $expected = array(
       'apple' => array(
@@ -1245,3 +1273,13 @@ public static function create(ContainerInterface $container) {
 if (!defined('DRUPAL_ROOT')) {
   define('DRUPAL_ROOT', dirname(dirname(substr(__DIR__, 0, -strlen(__NAMESPACE__)))));
 }
+}
+
+namespace {
+
+  /**
+   * Implements hook_entity_type_build().
+   */
+  function entity_manager_test_module_entity_type_build() {
+  }
+}
diff --git a/core/tests/Drupal/Tests/Core/Plugin/DefaultPluginManagerTest.php b/core/tests/Drupal/Tests/Core/Plugin/DefaultPluginManagerTest.php
index 4862ac7..fdc0ff4 100644
--- a/core/tests/Drupal/Tests/Core/Plugin/DefaultPluginManagerTest.php
+++ b/core/tests/Drupal/Tests/Core/Plugin/DefaultPluginManagerTest.php
@@ -71,8 +71,8 @@ protected function setUp() {
    * Tests the plugin manager with a disabled module.
    */
   public function testDefaultPluginManagerWithDisabledModule() {
-     $definitions = $this->expectedDefinitions;
-     $definitions['cherry'] = array(
+    $definitions = $this->expectedDefinitions;
+    $definitions['cherry'] = array(
       'id' => 'cherry',
       'label' => 'Cherry',
       'color' => 'red',
@@ -93,6 +93,31 @@ public function testDefaultPluginManagerWithDisabledModule() {
   }
 
   /**
+   * Tests the plugin manager and object plugin definitions.
+   */
+  public function testDefaultPluginManagerWithObjects() {
+    $definitions = $this->expectedDefinitions;
+    $definitions['cherry'] = (object) array(
+      'id' => 'cherry',
+      'label' => 'Cherry',
+      'color' => 'red',
+      'class' => 'Drupal\plugin_test\Plugin\plugin_test\fruit\Cherry',
+      'provider' => 'disabled_module',
+    );
+
+    $module_handler = $this->getMock('Drupal\Core\Extension\ModuleHandlerInterface');
+
+    $module_handler->expects($this->once())
+      ->method('moduleExists')
+      ->with('disabled_module')
+      ->will($this->returnValue(FALSE));
+
+    $plugin_manager = new TestPluginManager($this->namespaces, $definitions, $module_handler, 'test_alter_hook');
+
+    $this->assertEmpty($plugin_manager->getDefinition('cherry'), 'Plugin information is available');
+  }
+
+  /**
    * Tests the plugin manager with no cache and altering.
    */
   public function testDefaultPluginManager() {