diff --git a/core/modules/comment/lib/Drupal/comment/Tests/Views/CommentTestBase.php b/core/modules/comment/lib/Drupal/comment/Tests/Views/CommentTestBase.php
index 138c5d0..dabf53f 100644
--- a/core/modules/comment/lib/Drupal/comment/Tests/Views/CommentTestBase.php
+++ b/core/modules/comment/lib/Drupal/comment/Tests/Views/CommentTestBase.php
@@ -41,7 +41,7 @@ function setUp() {
     $this->drupalLogin($this->account);
 
     $this->node_user_posted = $this->drupalCreateNode();
-    $this->node_user_commented = $this->drupalCreateNode(array('uid' => $this->account2->uid));
+    $this->node_user_commented = $this->drupalCreateNode(array('uid' => $this->account2->id()));
 
     $comment = array(
       'uid' => $this->loggedInUser->id(),
diff --git a/core/modules/forum/forum.module b/core/modules/forum/forum.module
index 9dd3758..617b28f 100644
--- a/core/modules/forum/forum.module
+++ b/core/modules/forum/forum.module
@@ -501,7 +501,7 @@ function forum_comment_delete($comment) {
  * Implements hook_field_storage_pre_insert().
  */
 function forum_field_storage_pre_insert(EntityInterface $entity, &$skip_fields) {
-  if ($entity->entityType() instanceof NodeInterface && $entity->isPublished() && _forum_node_check_node_type($entity)) {
+  if ($entity->entityType() == 'node' && $entity->isPublished() && _forum_node_check_node_type($entity)) {
     $query = db_insert('forum_index')->fields(array('nid', 'title', 'tid', 'sticky', 'created', 'comment_count', 'last_comment_timestamp'));
     foreach ($entity->getTranslationLanguages() as $langcode => $language) {
       $translation = $entity->getTranslation($langcode);
@@ -525,7 +525,7 @@ function forum_field_storage_pre_insert(EntityInterface $entity, &$skip_fields)
 function forum_field_storage_pre_update(EntityInterface $entity, &$skip_fields) {
   $first_call = &drupal_static(__FUNCTION__, array());
 
-  if ($entity instanceof NodeInterface && _forum_node_check_node_type($entity)) {
+  if ($entity->entityType() == 'node' && _forum_node_check_node_type($entity)) {
 
     // If the node is published, update the forum index.
     if ($entity->isPublished()) {