diff --git a/core/lib/Drupal/Core/Entity/EntityManager.php b/core/lib/Drupal/Core/Entity/EntityManager.php
index 7771e3a..bf7cf09 100644
--- a/core/lib/Drupal/Core/Entity/EntityManager.php
+++ b/core/lib/Drupal/Core/Entity/EntityManager.php
@@ -408,7 +408,7 @@ protected function buildBaseFieldDefinitions($entity_type_id) {
     $keys = array_filter($entity_type->getKeys());
 
     // Fail with an exception for non-fieldable entity types.
-    if (!($entity_type instanceof ContentEntityTypeInterface)) {
+    if (!is_subclass_of($entity_type->getClass(), '\Drupal\Core\Entity\FieldableEntityInterface')) {
       throw new \LogicException(SafeMarkup::format('Getting the base fields is not supported for entity type @type.', array('@type' => $entity_type->getLabel())));
     }