diff --git a/core/modules/block/lib/Drupal/block/Tests/BlockPreprocessTest.php b/core/modules/block/lib/Drupal/block/Tests/BlockPreprocessTest.php
index 64fbb15..c399879 100644
--- a/core/modules/block/lib/Drupal/block/Tests/BlockPreprocessTest.php
+++ b/core/modules/block/lib/Drupal/block/Tests/BlockPreprocessTest.php
@@ -45,8 +45,11 @@ function testBlockClasses() {
 
     $variables = array();
     $variables['elements']['#block'] = $block;
-    $variables['elements']['#configuration'] = $block->getPlugin()->getConfiguration();
-    $variables['elements']['#plugin_id'] = $block->get('plugin');
+    $plugin = $block->getPlugin();
+    $variables['elements']['#configuration'] = $plugin->getConfiguration();
+    $variables['elements']['#plugin_id'] = $plugin->getPluginId();
+    $variables['elements']['#base_plugin_id'] = $plugin->getBasePluginId();
+    $variables['elements']['#derivative_plugin_id'] = $plugin->getDerivativeId();
     $variables['elements']['content'] = array();
 
     // Test adding a class to the block content.