diff --git a/core/modules/system/lib/Drupal/system/Plugin/ImageToolkitManager.php b/core/modules/system/lib/Drupal/system/Plugin/ImageToolkitManager.php
index 5d002b0..8df89bd 100644
--- a/core/modules/system/lib/Drupal/system/Plugin/ImageToolkitManager.php
+++ b/core/modules/system/lib/Drupal/system/Plugin/ImageToolkitManager.php
@@ -24,9 +24,7 @@ class ImageToolkitManager extends PluginManagerBase {
    *   keyed by the corresponding namespace to look for plugin implementations,
    */
   public function __construct(\Traversable $namespaces) {
-    $annotation_namespaces = array(
-      'Drupal\system\Plugin\Annotation' => DRUPAL_ROOT . '/core/modules/system/lib',
-    );
+    $annotation_namespaces = array('Drupal\system\Plugin\Annotation' => $namespaces['Drupal\system']);
     $this->discovery = new AnnotatedClassDiscovery('system', 'imagetoolkit', $namespaces, $annotation_namespaces, 'Drupal\system\Plugin\Annotation\ImageToolKit');
 
     $this->factory = new DefaultFactory($this->discovery);