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
@@ -160,7 +160,7 @@
    *
    * @var bool
    */
-  public $serializeCompleteEntityStructure = FALSE;
+  public $deepSerialization = FALSE;
 
   /**
    * {@inheritdoc}
@@ -447,7 +447,7 @@
     // Get the values of instantiated field objects, only serialize the values.
     foreach ($this->fields as $name => $fields) {
       foreach ($fields as $langcode => $field) {
-        $this->values[$name][$langcode] = $field->getValue();
+        $this->values[$name][$langcode] = $field->getSerializationValue($this->deepSerialization);
       }
     }
     $this->fields = array();
@@ -455,35 +455,33 @@
     $this->languages = NULL;
     $this->clearTranslationCache();
 
+    // As during the serialization process referenced entities might also have
+    // the "deepSerialization" flag set the only place of unsetting it remains
+    // in the sleep method right after the entity is prepared for the
+    // serialization and before executing it.
+    // @see \Drupal\Core\Field\EntityReferenceFieldItemList::getSerializationValue().
+    $this->deepSerialization = FALSE;
+
     return parent::__sleep();
   }
 
   /**
    * {@inheritdoc}
    */
-  public function __wakeup() {
-    parent::__wakeup();
-    // If the entity has been serialized with the flag
-    // "serializeCompleteEntityStructure" set to TRUE then the entity has been
-    // deeply serialized and in order to allow normal serialization on the
-    // unserialized entity we have to unset the flag.
-    $this->serializeCompleteEntityStructure = FALSE;
+  public function deepSerialize() {
+    // When running a deep serialization the flag "deepSerialization" has to be
+    // set in order to serialize referenced entities as well, which are
+    // referenced by field having the setting "serialize_embedded_entities" set
+    // to TRUE.
+    $this->deepSerialization = TRUE;
+    return serialize($this);
   }
 
   /**
    * {@inheritdoc}
    */
-  public function serializeWithCompleteStructure() {
-    // When running a deep serialization the flag
-    // "serializeCompleteEntityStructure" has to be set in order to serialize
-    // referenced entities as well, which are referenced by field having the
-    // setting "serialize_embedded_entities" set to TRUE.
-    $this->serializeCompleteEntityStructure = TRUE;
-    $serialized = serialize($this);
-    // After the deep serialization is ready we have to unset the flag in order
-    // to allow for normal serialization afterwards.
-    $this->serializeCompleteEntityStructure = FALSE;
-    return $serialized;
+  public function setDeepSerialization() {
+    $this->deepSerialization = TRUE;
   }
 
   /**
@@ -858,7 +856,7 @@
     $translation->enforceIsNew = &$this->enforceIsNew;
     $translation->newRevision = &$this->newRevision;
     $translation->entityKeys = &$this->entityKeys;
-    $translation->serializeCompleteEntityStructure = &$this->serializeCompleteEntityStructure;
+    $translation->deepSerialization = &$this->deepSerialization;
     $translation->translatableEntityKeys = &$this->translatableEntityKeys;
     $translation->translationInitialize = FALSE;
     $translation->typedData = NULL;
@@ -1137,11 +1135,10 @@
       $original_revision_id = $this->loadedRevisionId;
       $this->loadedRevisionId = &$original_revision_id;
 
-      // Ensure the serializeCompleteEntityStructure property is actually
-      // cloned by overwriting the original reference with one pointing to a
-      // copy of it.
-      $serializeCompleteEntityStructure = $this->serializeCompleteEntityStructure;
-      $this->serializeCompleteEntityStructure = &$serializeCompleteEntityStructure;
+      // Ensure the deepSerialization property is actually cloned by
+      // overwriting the original reference with one pointing to a copy of it.
+      $deepSerialization = $this->deepSerialization;
+      $this->deepSerialization = &$deepSerialization;
     }
   }
 
diff -u b/core/lib/Drupal/Core/Entity/ContentEntityInterface.php b/core/lib/Drupal/Core/Entity/ContentEntityInterface.php
--- b/core/lib/Drupal/Core/Entity/ContentEntityInterface.php
+++ b/core/lib/Drupal/Core/Entity/ContentEntityInterface.php
@@ -81,5 +81,16 @@
    *   The deeply serialized entity.
    */
-  public function serializeWithCompleteStructure();
+  public function deepSerialize();
+
+  /**
+   * Flags the entity for deep serialization.
+   *
+   * After calling this method and serializing the entity e.g.
+   * "serialize($entity);" a deep serialization will be performed and the flag
+   * will be automatically reset.
+   *
+   * @return $this
+   */
+  public function setDeepSerialization();
 
 }
diff -u b/core/lib/Drupal/Core/Field/EntityReferenceFieldItemList.php b/core/lib/Drupal/Core/Field/EntityReferenceFieldItemList.php
--- b/core/lib/Drupal/Core/Field/EntityReferenceFieldItemList.php
+++ b/core/lib/Drupal/Core/Field/EntityReferenceFieldItemList.php
@@ -13,31 +13,21 @@
   /**
    * {@inheritdoc}
    */
-  public function getValue($include_computed = FALSE) {
-    $values = array();
-    $serialize_embedded_entities = $this->isDeepSerializationActive();
-    if (!$include_computed) {
-      $include_computed = $serialize_embedded_entities;
-    }
-    foreach ($this->list as $delta => $item) {
-      $values[$delta] = $item->getValue($include_computed);
-      // If deep serialization is active then flag the referenced entities for
-      // deep serialization as well.
-      if (isset($values[$delta]['entity']) && $serialize_embedded_entities) {
-        $values[$delta]['entity']->serializeCompleteEntityStructure = TRUE;
+  public function getSerializationValue($deep_serialization) {
+    if ($deep_serialization) {
+      $serialize_embedded_entities = $this->getFieldDefinition()->getSetting('serialize_embedded_entities');
+      $values = $this->getValue($serialize_embedded_entities);
+      foreach ($values as $delta => $item_values) {
+        if (isset($values[$delta]['entity'])) {
+          $values[$delta]['entity']->setDeepSerialization();
+        }
       }
     }
-    return $values;
-  }
+    else {
+      $values = parent::getSerializationValue($deep_serialization);
+    }
 
-  /**
-   * Checks if deep serialization is active.
-   *
-   * @return bool
-   *   TRUE if deep serialization is active, FALSE otherwise.
-   */
-  protected function isDeepSerializationActive() {
-    return $this->getFieldDefinition()->getSetting('serialize_embedded_entities') && $this->getEntity()->serializeCompleteEntityStructure;
+    return $values;
   }
 
   /**
diff -u b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
--- b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
@@ -344,8 +344,8 @@
 
     $form['serialize_embedded_entities'] = array(
       '#type' => 'checkbox',
-      '#title' => $this->t('Serialize entity references together with the parent entity'),
-      '#description' => $this->t('If the field widget to be used for this field is an entity reference inline widget then the setting must be set.'),
+      '#title' => $this->t('Serialize entity references together with the parent entity when performing deep serialization of the parent entity.'),
+      '#description' => $this->t('If the field widget to be used for this field is an "entity reference inline widget" then the setting must be set.'),
       '#default_value' => $field->getSetting('serialize_embedded_entities'),
     );
 
diff -u b/core/modules/field/field.install b/core/modules/field/field.install
--- b/core/modules/field/field.install
+++ b/core/modules/field/field.install
@@ -6,7 +6,6 @@
  */
 
 use Drupal\Core\Field\Plugin\Field\FieldType\EntityReferenceItem;
-use Drupal\file\Plugin\Field\FieldType\FileItem;
 
 /**
  * Removes the stale 'target_bundle' storage setting on entity_reference fields.
@@ -130,7 +129,7 @@
       $settings = $field->get('settings');
 
       if (!isset($settings['serialize_embedded_entities'])) {
-        $settings['serialize_embedded_entities'] = is_subclass_of($class, FileItem::class) ? TRUE : FALSE;
+        $settings['serialize_embedded_entities'] = FALSE;
       }
 
       $field->set('settings', $settings)->save(TRUE);
reverted:
--- b/core/modules/field/tests/src/Kernel/Migrate/d6/MigrateFieldInstanceTest.php
+++ a/core/modules/field/tests/src/Kernel/Migrate/d6/MigrateFieldInstanceTest.php
@@ -81,7 +81,6 @@
       'uri_scheme' => 'public',
       'handler' => 'default:file',
       'handler_settings' => array(),
-      'serialize_embedded_entities' => true,
     );
     $field_settings = $field->getSettings();
     ksort($expected);
reverted:
--- b/core/modules/file/config/schema/file.schema.yml
+++ a/core/modules/file/config/schema/file.schema.yml
@@ -43,9 +43,6 @@
 base_file_field_field_settings:
   type: mapping
   mapping:
-    serialize_embedded_entities:
-      type: boolean
-      label: 'Serialize entity references together with the parent entity'
     handler:
       type: string
       label: 'Reference method'
reverted:
--- b/core/modules/file/src/Plugin/Field/FieldType/FileItem.php
+++ a/core/modules/file/src/Plugin/Field/FieldType/FileItem.php
@@ -49,7 +49,6 @@
       'file_directory' => '[date:custom:Y]-[date:custom:m]',
       'max_filesize' => '',
       'description_field' => 0,
-      'serialize_embedded_entities' => TRUE,
     ) + parent::defaultFieldSettings();
   }
 
reverted:
--- b/core/modules/file/src/Plugin/Field/FieldWidget/FileWidget.php
+++ a/core/modules/file/src/Plugin/Field/FieldWidget/FileWidget.php
@@ -3,10 +3,10 @@
 namespace Drupal\file\Plugin\Field\FieldWidget;
 
 use Drupal\Component\Utility\NestedArray;
-use Drupal\Core\Field\EntityReferenceInlineWidgetBase;
 use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Field\FieldItemListInterface;
 use Drupal\Core\Field\FieldStorageDefinitionInterface;
+use Drupal\Core\Field\WidgetBase;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
 use Drupal\Core\Render\Element;
@@ -27,7 +27,7 @@
  *   }
  * )
  */
+class FileWidget extends WidgetBase implements ContainerFactoryPluginInterface {
-class FileWidget extends EntityReferenceInlineWidgetBase implements ContainerFactoryPluginInterface {
 
   /**
    * {@inheritdoc}
reverted:
--- b/core/profiles/standard/config/install/field.field.node.article.field_image.yml
+++ a/core/profiles/standard/config/install/field.field.node.article.field_image.yml
@@ -32,7 +32,6 @@
     title: ''
     width: null
     height: null
-  serialize_embedded_entities: true
   handler: 'default:file'
   handler_settings: {  }
 field_type: image
reverted:
--- b/core/profiles/standard/config/install/field.field.user.user.user_picture.yml
+++ a/core/profiles/standard/config/install/field.field.user.user.user_picture.yml
@@ -32,7 +32,6 @@
     height: null
   alt_field_required: false
   title_field_required: false
-  serialize_embedded_entities: true
   handler: 'default:file'
   handler_settings: {  }
 field_type: image
diff -u b/core/tests/Drupal/KernelTests/Core/Entity/ContentEntitySerializationTest.php b/core/tests/Drupal/KernelTests/Core/Entity/ContentEntitySerializationTest.php
--- b/core/tests/Drupal/KernelTests/Core/Entity/ContentEntitySerializationTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Entity/ContentEntitySerializationTest.php
@@ -109,7 +109,7 @@
 
     $this->entityTestMulStorage->resetCache();
 
-    $serialized_entity = $entity_level_zero->serializeWithCompleteStructure();
+    $serialized_entity = $entity_level_zero->deepSerialize();
     $entity_level_zero = unserialize($serialized_entity);
     $this->assertEquals('entity level zero', $entity_level_zero->label());
     $this->assertEquals($deep_serialization ? 'entity level one' : $initial_entity_name, $entity_level_zero->$field_name->entity->label());
only in patch2:
unchanged:
--- a/core/lib/Drupal/Core/Field/FieldItemList.php
+++ b/core/lib/Drupal/Core/Field/FieldItemList.php
@@ -121,6 +121,13 @@ public function setValue($values, $notify = TRUE) {
   /**
    * {@inheritdoc}
    */
+  public function getSerializationValue($deep_serialization) {
+    return $this->getValue();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public function __get($property_name) {
     // For empty fields, $entity->field->property is NULL.
     if ($item = $this->first()) {
only in patch2:
unchanged:
--- a/core/lib/Drupal/Core/Field/FieldItemListInterface.php
+++ b/core/lib/Drupal/Core/Field/FieldItemListInterface.php
@@ -271,4 +271,14 @@ public static function processDefaultValue($default_value, FieldableEntityInterf
    */
   public function equals(FieldItemListInterface $list_to_compare);
 
+  /**
+   * Gets the data value prepared for serialization.
+   *
+   * @param bool $deep_serialization
+   *   Whether a deep serialization is running.
+   *
+   * @return mixed
+   */
+  public function getSerializationValue($deep_serialization);
+
 }