diff --git a/core/includes/language.inc b/core/includes/language.inc
index 976dd75..74cc832 100644
--- a/core/includes/language.inc
+++ b/core/includes/language.inc
@@ -8,6 +8,8 @@
  */
 
 use Drupal\Core\Language\Language;
+use Drupal\block\BlockPluginEvents;
+use Symfony\Component\EventDispatcher\GenericEvent;
 
 /**
  * No language negotiation. The default language is used.
@@ -209,6 +211,11 @@ function language_types_disable($types) {
 
   foreach ($types as $type) {
     unset($enabled_types[$type]);
+    // Inform the block plugin system you have removed a language.
+    if (\Drupal::moduleHandler()->moduleExists('block')) {
+      $event = new GenericEvent('language_block:' . $type);
+      \Drupal::service('event_dispatcher')->dispatch(BlockPluginEvents::PERMANENTLY_UNAVAILABLE, $event);
+    }
   }
 
   variable_set('language_types', $enabled_types);
diff --git a/core/modules/block/custom_block/lib/Drupal/custom_block/Plugin/Core/Entity/CustomBlock.php b/core/modules/block/custom_block/lib/Drupal/custom_block/Plugin/Core/Entity/CustomBlock.php
index 74dfc25..309da01 100644
--- a/core/modules/block/custom_block/lib/Drupal/custom_block/Plugin/Core/Entity/CustomBlock.php
+++ b/core/modules/block/custom_block/lib/Drupal/custom_block/Plugin/Core/Entity/CustomBlock.php
@@ -12,6 +12,8 @@
 use Drupal\Core\Entity\Annotation\EntityType;
 use Drupal\Core\Annotation\Translation;
 use Drupal\custom_block\CustomBlockInterface;
+use Drupal\block\BlockPluginEvents;
+use Symfony\Component\EventDispatcher\GenericEvent;
 
 /**
  * Defines the custom block entity class.
@@ -225,9 +227,8 @@ public function preSaveRevision(EntityStorageControllerInterface $storage_contro
    * {@inheritdoc}
    */
   public function delete() {
-    foreach ($this->getInstances() as $instance) {
-      $instance->delete();
-    }
+    $event = new GenericEvent('custom_block:' . $this->uuid->value);
+    \Drupal::service('event_dispatcher')->dispatch(BlockPluginEvents::PERMANENTLY_UNAVAILABLE, $event);
     parent::delete();
   }
 
diff --git a/core/modules/block/lib/Drupal/block/BlockPluginEvents.php b/core/modules/block/lib/Drupal/block/BlockPluginEvents.php
index 5ae4798..c4afebe 100644
--- a/core/modules/block/lib/Drupal/block/BlockPluginEvents.php
+++ b/core/modules/block/lib/Drupal/block/BlockPluginEvents.php
@@ -17,7 +17,7 @@ class BlockPluginEvents {
    *
    * This could be the case, when something is disabled but not deleted.
    */
-  const TEMPORARILY_UNAVAILABLE = 'temporary';
+  const TEMPORARILY_UNAVAILABLE = 'block.unavailable.temporarily';
 
   /**
    * This event is thrown when a block plugin is permanently unavailable.
@@ -25,6 +25,6 @@ class BlockPluginEvents {
    * This could be the case, when a module has been uninstalled or the data
    * from which a block plugin was derived was deleted.
    */
-  const PERMANENTLY_UNAVAILABLE = 'permanent';
+  const PERMANENTLY_UNAVAILABLE = 'block.unavailable.permanently';
 
 }