diff --git a/core/modules/block/lib/Drupal/block/BlockPluginBag.php b/core/modules/block/lib/Drupal/block/BlockPluginBag.php
index 12bca82..e71fcca 100644
--- a/core/modules/block/lib/Drupal/block/BlockPluginBag.php
+++ b/core/modules/block/lib/Drupal/block/BlockPluginBag.php
@@ -8,6 +8,7 @@
 namespace Drupal\block;
 
 use Drupal\Component\Plugin\Exception\PluginException;
+use Drupal\Component\Plugin\PluginManagerInterface;
 use Drupal\Core\Plugin\DefaultSinglePluginBag;
 
 /**
@@ -16,11 +17,27 @@
 class BlockPluginBag extends DefaultSinglePluginBag {
 
   /**
+   * The block ID this plugin bag belongs to.
+   *
+   * @var string
+   */
+  protected $blockId;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function __construct(PluginManagerInterface $manager, array $instance_ids, array $configuration, $block_id) {
+    parent::__construct($manager, $instance_ids, $configuration);
+
+    $this->blockId = $block_id;
+  }
+
+  /**
    * {@inheritdoc}
    */
   protected function initializePlugin($instance_id) {
     if (!$instance_id) {
-      throw new PluginException(format_string("The block '@block' did not specify a plugin.", array('@block' => $this->configuration['id'])));
+      throw new PluginException(format_string("The block '@block' did not specify a plugin.", array('@block' => $this->blockId)));
     }
 
     try {
diff --git a/core/modules/block/lib/Drupal/block/Plugin/Core/Entity/Block.php b/core/modules/block/lib/Drupal/block/Plugin/Core/Entity/Block.php
index 25f6b39..ac87707 100644
--- a/core/modules/block/lib/Drupal/block/Plugin/Core/Entity/Block.php
+++ b/core/modules/block/lib/Drupal/block/Plugin/Core/Entity/Block.php
@@ -105,9 +105,7 @@ class Block extends ConfigEntityBase implements BlockInterface {
   public function __construct(array $values, $entity_type) {
     parent::__construct($values, $entity_type);
 
-    $settings = $this->get('settings');
-    $settings['id'] = $this->id();
-    $this->pluginBag = new BlockPluginBag(\Drupal::service('plugin.manager.block'), array($this->plugin), $settings);
+    $this->pluginBag = new BlockPluginBag(\Drupal::service('plugin.manager.block'), array($this->plugin), $this->get('settings'), $this->id());
   }
 
   /**