diff --git a/core/modules/system/src/Tests/Image/ToolkitTest.php b/core/modules/system/src/Tests/Image/ToolkitTest.php
index caaed9f..b6c7a6a 100644
--- a/core/modules/system/src/Tests/Image/ToolkitTest.php
+++ b/core/modules/system/src/Tests/Image/ToolkitTest.php
@@ -77,19 +77,14 @@ function testApplyNoParameters() {
    * Tests image toolkit operations inheritance by derivative toolkits.
    */
   public function testDerivative() {
-    /** @var \Drupal\Core\ImageToolkit\ImageToolkitManager $manager */
-    $manager = $this->container->get('image.toolkit.manager');
-
-    /** @var \Drupal\Core\ImageToolkit\ImageToolkitInterface $toolkit */
-    $toolkit = $manager->createInstance('test:derived_toolkit');
+    $toolkit_manager = $this->container->get('image.toolkit.manager');
+    $operation_manager = $this->container->get('image.toolkit.operation.manager');
 
-    /** @var \Drupal\Core\ImageToolkit\ImageToolkitOperationManager $operation */
-    $operation = $this->container->get('image.toolkit.operation.manager');
+    $toolkit = $toolkit_manager->createInstance('test:derived_toolkit');
 
-    /** @var \Drupal\Core\ImageToolkit\ImageToolkitOperationInterface $blur */
-    $blur = $operation->getToolkitOperation($toolkit, 'blur');
-    /** @var \Drupal\Core\ImageToolkit\ImageToolkitOperationInterface $invert */
-    $invert = $operation->getToolkitOperation($toolkit, 'invert');
+    // Load an overwritten and an inherited operation.
+    $blur = $operation_manager->getToolkitOperation($toolkit, 'blur');
+    $invert = $operation_manager->getToolkitOperation($toolkit, 'invert');
 
     $this->assertEqual('foo_derived', $blur->getPluginId(), "'Blur' operation overwritten by derivative.");
     $this->assertEqual('bar', $invert->getPluginId(), '"Invert" operation inherited from base plugin.');