diff -u b/core/lib/Drupal/Core/Entity/ContentEntityBase.php b/core/lib/Drupal/Core/Entity/ContentEntityBase.php
--- b/core/lib/Drupal/Core/Entity/ContentEntityBase.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityBase.php
@@ -478,8 +478,8 @@
   /**
    * {@inheritdoc}
    */
-  public function setDeepSerialization() {
-    $this->deepSerialization = TRUE;
+  public function setDeepSerialization($deep_serialization = TRUE) {
+    $this->deepSerialization = $deep_serialization;
   }
 
   /**
diff -u b/core/lib/Drupal/Core/Entity/FieldableEntityInterface.php b/core/lib/Drupal/Core/Entity/FieldableEntityInterface.php
--- b/core/lib/Drupal/Core/Entity/FieldableEntityInterface.php
+++ b/core/lib/Drupal/Core/Entity/FieldableEntityInterface.php
@@ -252,7 +252,11 @@
    * will be automatically reset.
    *
+   * @param bool $deep_serialization
+   *   TRUE if deep serialization should be performed when the entity is being
+   *   serialized, FALSE otherwise. Defaults to TRUE.
+   *
    * @return $this
    */
-  public function setDeepSerialization();
+  public function setDeepSerialization($deep_serialization = TRUE);
 
 }