diff --git a/core/modules/block/custom_block/src/Plugin/Derivative/CustomBlock.php b/core/modules/block/custom_block/src/Plugin/Derivative/CustomBlock.php
deleted file mode 100644
index 976703d..0000000
--- a/core/modules/block/custom_block/src/Plugin/Derivative/CustomBlock.php
+++ /dev/null
@@ -1,28 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains \Drupal\custom_block\Plugin\Derivative\CustomBlock.
- */
-
-namespace Drupal\custom_block\Plugin\Derivative;
-
-use Drupal\Component\Plugin\Derivative\DeriverBase;
-use Drupal\Core\Plugin\Discovery\ContainerDeriverInterface;
-
-/**
- * Retrieves block plugin definitions for all custom blocks.
- */
-class CustomBlock extends DeriverBase {
-  /**
-   * {@inheritdoc}
-   */
-  public function getDerivativeDefinitions($base_plugin_definition) {
-    $custom_blocks = entity_load_multiple('custom_block');
-    foreach ($custom_blocks as $custom_block) {
-      $this->derivatives[$custom_block->uuid()] = $base_plugin_definition;
-      $this->derivatives[$custom_block->uuid()]['admin_label'] = $custom_block->label();
-    }
-    return parent::getDerivativeDefinitions($base_plugin_definition);
-  }
-}