diff -u b/core/lib/Drupal/Component/Plugin/PluginManagerBase.php b/core/lib/Drupal/Component/Plugin/PluginManagerBase.php
--- b/core/lib/Drupal/Component/Plugin/PluginManagerBase.php
+++ b/core/lib/Drupal/Component/Plugin/PluginManagerBase.php
@@ -7,7 +7,6 @@
 
 namespace Drupal\Component\Plugin;
 
-use Drupal\Component\Utility\NestedArray;
 use Drupal\Component\Plugin\Discovery\CachedDiscoveryInterface;
 
 /**