diff --git a/core/modules/block/lib/Drupal/block/Tests/BlockTestBase.php b/core/modules/block/lib/Drupal/block/Tests/BlockTestBase.php
index 5c8bf6a..005bff6 100644
--- a/core/modules/block/lib/Drupal/block/Tests/BlockTestBase.php
+++ b/core/modules/block/lib/Drupal/block/Tests/BlockTestBase.php
@@ -68,7 +68,6 @@ function setUp() {
     );
 
     $default_theme = variable_get('theme_default', 'stark');
-    $manager = $this->container->get('plugin.manager.block');
     $instances = config_get_storage_names_with_prefix('plugin.core.block.' . $default_theme);
     foreach ($instances as $plugin_id) {
       \Drupal::config($plugin_id)->delete();