diff --git a/core/modules/block_content/src/Form/BlockContentDeleteForm.php b/core/modules/block_content/src/Form/BlockContentDeleteForm.php
index fe0759cc16d..3a77b65f65b 100644
--- a/core/modules/block_content/src/Form/BlockContentDeleteForm.php
+++ b/core/modules/block_content/src/Form/BlockContentDeleteForm.php
@@ -3,7 +3,6 @@
 namespace Drupal\block_content\Form;
 
 use Drupal\Core\Entity\ContentEntityDeleteForm;
-use Drupal\Core\Form\FormStateInterface;
 
 /**
  * Provides a confirmation form for deleting a custom block entity.
@@ -15,15 +14,12 @@ class BlockContentDeleteForm extends ContentEntityDeleteForm {
   /**
    * {@inheritdoc}
    */
-  public function buildForm(array $form, FormStateInterface $form_state) {
+  public function getDescription() {
     $instances = $this->entity->getInstances();
-
-    $form['message'] = [
-      '#markup' => $this->formatPlural(count($instances), 'This will also remove 1 placed block instance.', 'This will also remove @count placed block instances.'),
-      '#access' => !empty($instances),
-    ];
-
-    return parent::buildForm($form, $form_state);
+    if (!empty($instances)) {
+      return $this->formatPlural(count($instances), 'This will also remove 1 placed block instance. This action cannot be undone.', 'This will also remove @count placed block instances. This action cannot be undone.');
+    }
+    return parent::getDescription();
   }
 
 }