diff --git a/core/modules/comment/src/CommentForm.php b/core/modules/comment/src/CommentForm.php
index a8fc4c1..d032bdb 100644
--- a/core/modules/comment/src/CommentForm.php
+++ b/core/modules/comment/src/CommentForm.php
@@ -40,11 +40,11 @@ class CommentForm extends ContentEntityForm {
   protected $renderer;
 
   /**
-   * The current entity.
+   * The commented entity obtained from route.
    *
    * @var \Drupal\node\EntityInterface
    */
-  protected $currentEntity;
+  protected $commentedEntity;
 
   /**
    * {@inheritdoc}
@@ -83,10 +83,16 @@ public function __construct(EntityManagerInterface $entity_manager, AccountInter
     // Get node entity from route match.
     $parameters = $route_match->getParameters();
     if ($parameters->has('node')) {
-      $this->currentEntity = $parameters->get('node');
+      $this->commentedEntity = $parameters->get('node');
     }
     elseif ($parameters->has('entity')) {
-      $this->currentEntity = $parameters->get('entity');
+      $this->commentedEntity = $parameters->get('entity');
+    }
+    elseif ($parameters->has('comment')) {
+      $comment = $parameters->get('comment');
+      $this->commentedEntity = $this->entityManager
+        ->getStorage($comment->getCommentedEntityTypeId())
+        ->load($comment->getCommentedEntityId());
     }
   }
 
@@ -125,9 +131,9 @@ public function form(array $form, FormStateInterface $form_state) {
 
     // If not replying to a comment, use our dedicated page callback for new
     // Comments on entities.
-    if (isset($this->currentEntity) &&
-      $this->currentEntity->getEntityTypeId() == $entity->getEntityTypeId() &&
-      $this->currentEntity->id() == $entity->id() && !$comment->id() &&
+    if (isset($this->commentedEntity) &&
+      $this->commentedEntity->getEntityTypeId() == $entity->getEntityTypeId() &&
+      $this->commentedEntity->id() == $entity->id() && !$comment->id() &&
       !$comment->hasParentComment()) {
       $form['#action'] = $this->url('comment.reply', [
         'entity_type' => $entity->getEntityTypeId(),
@@ -424,9 +430,9 @@ public function save(array $form, FormStateInterface $form_state) {
       drupal_set_message($this->t('Comment: unauthorized comment submitted or comment submitted to a closed post %subject.', ['%subject' => $comment->getSubject()]), 'error');
       // Redirect the user to the entity they are commenting on.
     }
-    if (isset($this->currentEntity) &&
-      $this->currentEntity->getEntityTypeId() == $entity->getEntityTypeId() &&
-      $this->currentEntity->id() == $entity->id() && $uri->access()) {
+    if (isset($this->commentedEntity) &&
+      $this->commentedEntity->getEntityTypeId() == $entity->getEntityTypeId() &&
+      $this->commentedEntity->id() == $entity->id() && $uri->access()) {
       $form_state->setRedirectUrl($uri);
     }
   }
diff --git a/core/modules/comment/tests/src/Functional/CommentBlockContentTest.php b/core/modules/comment/tests/src/Functional/CommentBlockContentTest.php
index de4ac15..1272d06 100644
--- a/core/modules/comment/tests/src/Functional/CommentBlockContentTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentBlockContentTest.php
@@ -7,14 +7,18 @@
 use Drupal\Component\Utility\Unicode;
 use Drupal\Core\Url;
 use Drupal\comment\Entity\CommentType;
+use Drupal\comment\Tests\CommentTestTrait;
 use Drupal\user\RoleInterface;
+use Drupal\Tests\BrowserTestBase;
 
 /**
  * Tests use of comment field on entity-type without a canonical path.
  *
  * @group comment
  */
-class CommentBlockContentTest extends CommentTestBase {
+class CommentBlockContentTest extends BrowserTestBase {
+
+  use CommentTestTrait;
 
   /**
    * Modules to install.