diff --git a/core/lib/Drupal/Core/Entity/EntityManager.php b/core/lib/Drupal/Core/Entity/EntityManager.php
index 28a7a74..bcbc6bb 100644
--- a/core/lib/Drupal/Core/Entity/EntityManager.php
+++ b/core/lib/Drupal/Core/Entity/EntityManager.php
@@ -289,8 +289,8 @@ public function getAdminPath($entity_type, $bundle) {
    * @param string $entity_type
    *   The entity type to get field definitions for.
    * @param string $bundle
-   *   (optional) The entity bundle for which to get field definitions. If FALSE
-   *   is passed, no bundle-specific fields are included. Defaults to FALSE.
+   *   (optional) The entity bundle for which to get field definitions. If NULL
+   *   is passed, no bundle-specific fields are included. Defaults to NULL.
    *
    * @return array
    *   An array of field definitions of entity fields, keyed by field
@@ -305,7 +305,7 @@ public function getAdminPath($entity_type, $bundle) {
    * @see \Drupal\Core\TypedData\TypedDataManager::create()
    * @see \Drupal\Core\Entity\EntityManager::getFieldDefinitionsByConstraints()
    */
-  public function getFieldDefinitions($entity_type, $bundle = FALSE) {
+  public function getFieldDefinitions($entity_type, $bundle = NULL) {
     if (!isset($this->entityFieldInfo[$entity_type])) {
       // First, try to load from cache.
       $cid = 'entity_field_definitions:' . $entity_type . ':' . $this->languageManager->getLanguage(LANGUAGE_TYPE_INTERFACE)->langcode;
@@ -381,7 +381,7 @@ public function getFieldDefinitions($entity_type, $bundle = FALSE) {
    */
   public function getFieldDefinitionsByConstraints($entity_type, array $constraints) {
     // @todo: Add support for specifying multiple bundles.
-    return $this->getFieldDefinitions($entity_type, isset($constraints['Bundle']) ? $constraints['Bundle'] : FALSE);
+    return $this->getFieldDefinitions($entity_type, isset($constraints['Bundle']) ? $constraints['Bundle'] : NULL);
   }
 
 }