diff --git a/core/lib/Drupal/Core/Entity/EntityDisplayBase.php b/core/lib/Drupal/Core/Entity/EntityDisplayBase.php
index 25bf7644d6..ee07817187 100644
--- a/core/lib/Drupal/Core/Entity/EntityDisplayBase.php
+++ b/core/lib/Drupal/Core/Entity/EntityDisplayBase.php
@@ -114,13 +114,6 @@ abstract class EntityDisplayBase extends ConfigEntityBase implements EntityDispl
    */
   protected $renderer;
 
-  /**
-   * Stores serializable keys which is used in __sleep()/__wakeup().
-   *
-   * @var string[]
-   */
-  protected $serializedKeys;
-
   /**
    * {@inheritdoc}
    */
@@ -549,8 +542,8 @@ public function __sleep() {
     // Keep track of the serialized keys, to avoid calling toArray() again in
     // __wakeup(). Because of the way __sleep() works, the data has to be
     // present in the object to be included in the serialized values.
-    $keys[] = 'serializedKeys';
-    $this->serializedKeys = $keys;
+    $keys[] = '_serializedKeys';
+    $this->_serializedKeys = $keys;
     return $keys;
   }
 
@@ -560,8 +553,8 @@ public function __sleep() {
   public function __wakeup() {
     // Determine what were the properties from toArray() that were saved in
     // __sleep().
-    $keys = $this->serializedKeys;
-    unset($this->serializedKeys);
+    $keys = $this->_serializedKeys;
+    unset($this->_serializedKeys);
     $values = array_intersect_key(get_object_vars($this), array_flip($keys));
     // Run those values through the __construct(), as if they came from a
     // regular entity load.
diff --git a/core/modules/user/src/Entity/User.php b/core/modules/user/src/Entity/User.php
index 766b68daea..1e41b11efc 100644
--- a/core/modules/user/src/Entity/User.php
+++ b/core/modules/user/src/Entity/User.php
@@ -74,8 +74,6 @@ class User extends ContentEntityBase implements UserInterface {
    * @var \Drupal\user\UserInterface
    */
   protected static $anonymousUser;
-  // phpcs:disable Drupal.Classes.PropertyDeclaration
-  public $_skipProtectedUserFieldConstraint;
 
   /**
    * {@inheritdoc}