diff --git a/core/lib/Drupal/Core/Plugin/CategorizingPluginManagerTrait.php b/core/lib/Drupal/Core/Plugin/CategorizingPluginManagerTrait.php
index 66fa31c..b3cc23b 100644
--- a/core/lib/Drupal/Core/Plugin/CategorizingPluginManagerTrait.php
+++ b/core/lib/Drupal/Core/Plugin/CategorizingPluginManagerTrait.php
@@ -24,13 +24,6 @@
   use StringTranslationTrait;
 
   /**
-   * An array of all available modules and their data.
-   *
-   * @var array
-   */
-  protected $moduleData;
-
-  /**
    * Processes a plugin definition to ensure there is a category.
    *
    * If the definition lacks a category, it defaults to the providing module.
@@ -43,31 +36,43 @@ protected function processDefinitionCategory(&$definition) {
     if (empty($definition['category'])) {
       // Default to the human readable module name if the provider is a module;
       // otherwise the provider machine name is used.
-      $definition['category'] = $this->getModuleName($definition['provider']);
+      $definition['category'] = $this->getProviderName($definition['provider']);
     }
   }
 
   /**
-   * Gets the name of the module.
+   * Gets the name of a provider.
    *
-   * @param string $module
-   *   The machine name of a module.
+   * @param string $provider
+   *   The machine name of a plugin provider.
    *
    * @return string
    *   The human-readable module name if it exists, otherwise the
-   *   machine-readable module name.
+   *   machine-readable name passed.
    */
-  protected function getModuleName($module) {
-    // Gather module data.
-    if (!isset($this->moduleData)) {
-      $this->moduleData = system_get_info('module');
-    }
+  protected function getProviderName($provider) {
+    $list = $this->getModuleHandler()->getModuleList();
     // If the module exists, return its human-readable name.
-    if (isset($this->moduleData[$module])) {
-      return $this->t($this->moduleData[$module]['name']);
+    if (isset($list[$provider])) {
+      return $this->getModuleHandler()->getName($provider);
     }
     // Otherwise, return the machine name.
-    return $module;
+    return $provider;
+  }
+
+  /**
+   * Returns the module handler used.
+   *
+   * @return \Drupal\Core\Extension\ModuleHandlerInterface
+   *   The module handler.
+   */
+  public function getModuleHandler() {
+    // If the class has an injected module handler, use it. Otherwise fall back
+    // to fetch it from the service container.
+    if (isset($this->moduleHandler)) {
+      return $this->moduleHandler;
+    }
+    return \Drupal::moduleHandler();
   }
 
   /**
@@ -75,6 +80,7 @@ protected function getModuleName($module) {
    */
   public function getCategories() {
     /** @var \Drupal\Core\Plugin\CategorizingPluginManagerTrait|\Drupal\Component\Plugin\PluginManagerInterface $this */
+    // Fetch all categories from definitions and remove duplicates.
     $categories = array_unique(array_values(array_map(function ($definition) {
       return $definition['category'];
     }, $this->getDefinitions())));
diff --git a/core/tests/Drupal/Tests/Core/Plugin/CategorizingPluginManagerTraitTest.php b/core/tests/Drupal/Tests/Core/Plugin/CategorizingPluginManagerTraitTest.php
index 8c6fee9..db67ad7 100644
--- a/core/tests/Drupal/Tests/Core/Plugin/CategorizingPluginManagerTraitTest.php
+++ b/core/tests/Drupal/Tests/Core/Plugin/CategorizingPluginManagerTraitTest.php
@@ -5,152 +5,149 @@
  * Contains \Drupal\Tests\Core\Plugin\CategorizingPluginManagerTraitTest.
  */
 
-namespace Drupal\Tests\Core\Plugin {
+namespace Drupal\Tests\Core\Plugin;
 
-  use Drupal\Component\Plugin\CategorizingPluginManagerInterface;
-  use Drupal\Core\Plugin\CategorizingPluginManagerTrait;
-  use Drupal\Core\Plugin\DefaultPluginManager;
-  use Drupal\Tests\UnitTestCase;
+use Drupal\Component\Plugin\CategorizingPluginManagerInterface;
+use Drupal\Core\Extension\ModuleHandlerInterface;
+use Drupal\Core\Plugin\CategorizingPluginManagerTrait;
+use Drupal\Core\Plugin\DefaultPluginManager;
+use Drupal\Tests\UnitTestCase;
+
+/**
+ * @coversDefaultClass \Drupal\Core\Plugin\CategorizingPluginManagerTrait
+ * @group Plugin
+ */
+class CategorizingPluginManagerTraitTest extends UnitTestCase {
 
   /**
-   * @coversDefaultClass \Drupal\Core\Plugin\CategorizingPluginManagerTrait
-   * @group Plugin
+   * The plugin manager to test.
+   *
+   * @var \Drupal\Component\Plugin\CategorizingPluginManagerInterface|\PHPUnit_Framework_MockObject_MockObject
    */
-  class CategorizingPluginManagerTraitTest extends UnitTestCase {
-
-    /**
-     * The plugin manager to test.
-     *
-     * @var \Drupal\Component\Plugin\CategorizingPluginManagerInterface|\PHPUnit_Framework_MockObject_MockObject
-     */
-    protected $pluginManager;
-
-    /**
-     * {@inheritdoc}
-     */
-    protected function setUp() {
-      $this->pluginManager = new CategorizingPluginManagerImpl();
-      $this->pluginManager->setStringTranslation($this->getStringTranslationStub());
-    }
-
-    /**
-     * @covers ::getCategories
-     */
-    public function testGetCategories() {
-      $this->assertSame(array_values($this->pluginManager->getCategories()), [
-          'fruits',
-          'vegetables',
-        ]);
-    }
-
-    /**
-     * @covers ::getSortedDefinitions
-     */
-    public function testGetSortedDefinitions() {
-      $sorted = $this->pluginManager->getSortedDefinitions();
-      $this->assertSame(array_keys($sorted), ['apple', 'mango', 'cucumber']);
-    }
-
-    /**
-     * @covers ::getGroupedDefinitions
-     */
-    public function testGetGroupedDefinitions() {
-      $grouped = $this->pluginManager->getGroupedDefinitions();
-      $this->assertSame(array_keys($grouped), ['fruits', 'vegetables']);
-      $this->assertSame(array_keys($grouped['fruits']), ['apple', 'mango']);
-      $this->assertSame(array_keys($grouped['vegetables']), ['cucumber']);
-    }
-
-    /**
-     * @covers ::processDefinitionCategory
-     */
-    public function testProcessDefinitionCategory() {
-      // Existing category.
-      $definition = [
-        'label' => 'some',
-        'provider' => 'core',
-        'category' => 'bag',
-      ];
-      $this->pluginManager->processDefinition($definition, 'some');
-      $this->assertSame($definition['category'], 'bag');
-
-      // No category, provider without label.
-      $definition = [
-        'label' => 'some',
-        'provider' => 'core',
-      ];
-      $this->pluginManager->processDefinition($definition, 'some');
-      $this->assertSame($definition['category'], 'core');
-
-      // No category, provider is module with label.
-      $definition = [
-        'label' => 'some',
-        'provider' => 'node',
-      ];
-      $this->pluginManager->processDefinition($definition, 'some');
-      $this->assertSame($definition['category'], 'Node');
-    }
+  protected $pluginManager;
 
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    $module_handler = $this->getMock('Drupal\Core\Extension\ModuleHandlerInterface');
+    $module_handler->expects($this->any())
+      ->method('getModuleList')
+      ->willReturn(['node' => []]);
+    $module_handler->expects($this->any())
+      ->method('getName')
+      ->with('node')
+      ->willReturn('Node');
+
+    $this->pluginManager = new CategorizingPluginManager($module_handler);
+    $this->pluginManager->setStringTranslation($this->getStringTranslationStub());
   }
 
   /**
-   * Class that allows testing the trait.
+   * @covers ::getCategories
    */
-  class CategorizingPluginManagerImpl extends DefaultPluginManager implements CategorizingPluginManagerInterface {
-
-    use CategorizingPluginManagerTrait;
-
-    /**
-     * Replace the constructor so we can instantiate a stub.
-     */
-    public function __construct() {
-    }
-
-    /**
-     * {@inheritdoc}
-     *
-     * Provides some test definitions to the trait.
-     */
-    public function getDefinitions() {
-      return [
-        'cucumber' => [
-          'label' => 'cucumber',
-          'category' => 'vegetables',
-        ],
-        'apple' => [
-          'label' => 'apple',
-          'category' => 'fruits',
-        ],
-        'mango' => [
-          'label' => 'mango',
-          'category' => 'fruits',
-        ],
-      ];
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function processDefinition(&$definition, $plugin_id) {
-      parent::processDefinition($definition, $plugin_id);
-      $this->processDefinitionCategory($definition);
-    }
+  public function testGetCategories() {
+    $this->assertSame(array_values($this->pluginManager->getCategories()), [
+        'fruits',
+        'vegetables',
+      ]);
+  }
 
+  /**
+   * @covers ::getSortedDefinitions
+   */
+  public function testGetSortedDefinitions() {
+    $sorted = $this->pluginManager->getSortedDefinitions();
+    $this->assertSame(array_keys($sorted), ['apple', 'mango', 'cucumber']);
+  }
+
+  /**
+   * @covers ::getGroupedDefinitions
+   */
+  public function testGetGroupedDefinitions() {
+    $grouped = $this->pluginManager->getGroupedDefinitions();
+    $this->assertSame(array_keys($grouped), ['fruits', 'vegetables']);
+    $this->assertSame(array_keys($grouped['fruits']), ['apple', 'mango']);
+    $this->assertSame(array_keys($grouped['vegetables']), ['cucumber']);
+  }
+
+  /**
+   * @covers ::processDefinitionCategory
+   */
+  public function testProcessDefinitionCategory() {
+    // Existing category.
+    $definition = [
+      'label' => 'some',
+      'provider' => 'core',
+      'category' => 'bag',
+    ];
+    $this->pluginManager->processDefinition($definition, 'some');
+    $this->assertSame($definition['category'], 'bag');
+
+    // No category, provider without label.
+    $definition = [
+      'label' => 'some',
+      'provider' => 'core',
+    ];
+    $this->pluginManager->processDefinition($definition, 'some');
+    $this->assertSame($definition['category'], 'core');
+
+    // No category, provider is module with label.
+    $definition = [
+      'label' => 'some',
+      'provider' => 'node',
+    ];
+    $this->pluginManager->processDefinition($definition, 'some');
+    $this->assertSame($definition['category'], 'Node');
   }
 
 }
 
-namespace {
+/**
+ * Class that allows testing the trait.
+ */
+class CategorizingPluginManager extends DefaultPluginManager implements CategorizingPluginManagerInterface {
+
+  use CategorizingPluginManagerTrait;
 
   /**
-   * "Mocks" system_get_info() as needed for the test.
+   * Replace the constructor so we can instantiate a stub.
+   *
+   * @param \Drupal\Core\Extension\ModuleHandlerInterface|\PHPUnit_Framework_MockObject_MockObject $module_handler
+   *   The module handler.
    */
-  if (!function_exists('system_get_info')) {
+  public function __construct(ModuleHandlerInterface $module_handler) {
+    $this->moduleHandler = $module_handler;
+  }
 
-    function system_get_info($type, $name = NULL) {
-      return ['node' => ['name' => 'Node']];
-    }
+  /**
+   * {@inheritdoc}
+   *
+   * Provides some test definitions to the trait.
+   */
+  public function getDefinitions() {
+    return [
+      'cucumber' => [
+        'label' => 'cucumber',
+        'category' => 'vegetables',
+      ],
+      'apple' => [
+        'label' => 'apple',
+        'category' => 'fruits',
+      ],
+      'mango' => [
+        'label' => 'mango',
+        'category' => 'fruits',
+      ],
+    ];
+  }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function processDefinition(&$definition, $plugin_id) {
+    parent::processDefinition($definition, $plugin_id);
+    $this->processDefinitionCategory($definition);
   }
 
 }