diff --git a/core/tests/Drupal/Tests/Component/Plugin/MockFallbackPluginManager.php b/core/tests/Drupal/Tests/Component/Plugin/MockFallbackPluginManager.php
deleted file mode 100644
index a4076bf..0000000
--- a/core/tests/Drupal/Tests/Component/Plugin/MockFallbackPluginManager.php
+++ /dev/null
@@ -1,30 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains \Drupal\Tests\Component\Plugin\MockFallbackPluginManager.
- */
-
-namespace Drupal\Tests\Component\Plugin;
-
-use Drupal\Component\Plugin\FallbackPluginManagerInterface;
-use Drupal\Component\Plugin\PluginManagerBase;
-
-/**
- * Mocks \Drupal\Component\Plugin\FallbackPluginManagerInterface.
- *
- * We have to mock \Drupal\Component\Plugin\FallbackPluginManagerInterface for
- * \Drupal\Tests\Component\Plugin\PluginManagerBaseTest here so that we can
- * implement ::getFallbackPluginId().
- */
-class MockFallbackPluginManager extends PluginManagerBase implements FallbackPluginManagerInterface {
-
-  /**
-   * {@inheritdoc}
-   */
-  public function getFallbackPluginId($plugin_id, array $configuration = array()) {
-    // Minimally implement getFallbackPluginId so that we can test it.
-    return $plugin_id . '_fallback';
-  }
-
-}
diff --git a/core/tests/Drupal/Tests/Component/Plugin/PluginManagerBaseTest.php b/core/tests/Drupal/Tests/Component/Plugin/PluginManagerBaseTest.php
index 3c5743a..173928d 100644
--- a/core/tests/Drupal/Tests/Component/Plugin/PluginManagerBaseTest.php
+++ b/core/tests/Drupal/Tests/Component/Plugin/PluginManagerBaseTest.php
@@ -12,7 +12,6 @@
 
 /**
  * @coversDefaultClass \Drupal\Component\Plugin\PluginManagerBase
- * @uses Drupal\Component\Plugin\Exception\PluginNotFoundException
  * @group Plugin
  */
 class PluginManagerBaseTest extends UnitTestCase {
@@ -73,14 +72,14 @@ public function testCreateInstance() {
    * @covers ::createInstance
    */
   public function testCreateInstanceFallback() {
-    // We mock our special mock-class which extends PluginManagerBase and also
+    // We use our special stub class which extends PluginManagerBase and also
     // implements FallbackPluginManagerInterface.
-    $manager = new MockFallbackPluginManager();
-    // Put our mocked factory on the base object.
+    $manager = new StubFallbackPluginManager();
+    // Put our stubbed factory on the base object.
     $factory_ref = new \ReflectionProperty($manager, 'factory');
     $factory_ref->setAccessible(TRUE);
 
-    // Finally the test.
+    // Set up the configuration array.
     $configuration_array = array('config' => 'something');
 
     // Test with fallback interface and valid plugin_id.
diff --git a/core/tests/Drupal/Tests/Component/Plugin/StubFallbackPluginManager.php b/core/tests/Drupal/Tests/Component/Plugin/StubFallbackPluginManager.php
new file mode 100644
index 0000000..12eca79
--- /dev/null
+++ b/core/tests/Drupal/Tests/Component/Plugin/StubFallbackPluginManager.php
@@ -0,0 +1,33 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Tests\Component\Plugin\StubFallbackPluginManager.
+ */
+
+namespace Drupal\Tests\Component\Plugin;
+
+use Drupal\Component\Plugin\FallbackPluginManagerInterface;
+use Drupal\Component\Plugin\PluginManagerBase;
+
+/**
+ * Stubs \Drupal\Component\Plugin\FallbackPluginManagerInterface.
+ *
+ * We have to stub \Drupal\Component\Plugin\FallbackPluginManagerInterface for
+ * \Drupal\Tests\Component\Plugin\PluginManagerBaseTest so that we can
+ * implement ::getFallbackPluginId().
+ *
+ * We do this so we can have it just return the plugin ID passed to it, with
+ * '_fallback' appended.
+ */
+class StubFallbackPluginManager extends PluginManagerBase implements FallbackPluginManagerInterface {
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFallbackPluginId($plugin_id, array $configuration = array()) {
+    // Minimally implement getFallbackPluginId so that we can test it.
+    return $plugin_id . '_fallback';
+  }
+
+}