diff --git a/core/lib/Drupal/Core/Entity/EntityType.php b/core/lib/Drupal/Core/Entity/EntityType.php
index 60f3315..09767fb 100644
--- a/core/lib/Drupal/Core/Entity/EntityType.php
+++ b/core/lib/Drupal/Core/Entity/EntityType.php
@@ -13,7 +13,7 @@
  * @ingroup entity_api
  */
 class EntityType implements EntityTypeInterface {
-  
+
   use StringTranslationTrait;
 
   /**
diff --git a/core/lib/Drupal/Core/Field/FieldModuleUninstallValidator.php b/core/lib/Drupal/Core/Field/FieldModuleUninstallValidator.php
index 05300f1..d1adaa9 100644
--- a/core/lib/Drupal/Core/Field/FieldModuleUninstallValidator.php
+++ b/core/lib/Drupal/Core/Field/FieldModuleUninstallValidator.php
@@ -2,7 +2,6 @@
 
 namespace Drupal\Core\Field;
 
-use Drupal\Core\Entity\ContentEntityTypeInterface;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\Entity\FieldableEntityStorageInterface;
 use Drupal\Core\Extension\ModuleUninstallValidatorInterface;
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
index 22d6e08..e8832f3 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
@@ -4,7 +4,6 @@
 
 use Drupal\Component\Utility\Html;
 use Drupal\Component\Utility\NestedArray;
-use Drupal\Core\Entity\ContentEntityTypeInterface;
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\EntityTypeInterface;
 use Drupal\Core\Entity\TypedData\EntityDataDefinition;
diff --git a/core/modules/comment/comment.views.inc b/core/modules/comment/comment.views.inc
index 6e68c7f..4e598ee 100644
--- a/core/modules/comment/comment.views.inc
+++ b/core/modules/comment/comment.views.inc
@@ -22,7 +22,7 @@ function comment_views_data_alter(&$data) {
 
   // Provide a integration for each entity type with fields except comment.
   foreach (\Drupal::entityManager()->getDefinitions() as $entity_type_id => $entity_type) {
-    if ($entity_type_id == 'comment' || !$entity_type->getBaseTable()) {
+    if ($entity_type_id == 'comment' || !$entity_type->isSubclassOf('\Drupal\Core\Entity\ContentEntityInterface') || !$entity_type->getBaseTable()) {
       continue;
     }
 
diff --git a/core/modules/comment/src/CommentManager.php b/core/modules/comment/src/CommentManager.php
index 49aef42..8fdeb4e 100644
--- a/core/modules/comment/src/CommentManager.php
+++ b/core/modules/comment/src/CommentManager.php
@@ -100,7 +100,7 @@ public function __construct(EntityManagerInterface $entity_manager, QueryFactory
    */
   public function getFields($entity_type_id) {
     $entity_type = $this->entityManager->getDefinition($entity_type_id);
-    if (!$entity_type->isSubclassOf('\Drupal\Core\Entity\FieldableEntityInterface')) {
+    if (!$entity_type instanceof ContentEntityTypeInterface) {
       // Early return, only content types can carry comment fields.
       return array();
     }