diff -u b/core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php b/core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php --- b/core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php +++ b/core/lib/Drupal/Core/Config/Entity/ConfigEntityBase.php @@ -277,7 +277,7 @@ */ public function __sleep() { // Only serialize properties from getExportProperties(). - $keys = array_keys($this->getExportProperties()); + $keys = array_keys(array_intersect_key($this->getExportProperties(), get_object_vars($this))); $keys[] = 'entityTypeId'; return $keys; }