diff --git a/core/modules/system/tests/modules/entity_test/entity_test.module b/core/modules/system/tests/modules/entity_test/entity_test.module
index 46ddd90..30b306f 100644
--- a/core/modules/system/tests/modules/entity_test/entity_test.module
+++ b/core/modules/system/tests/modules/entity_test/entity_test.module
@@ -402,7 +402,11 @@ function entity_test_entity_test_insert($entity) {
  * Implements hook_entity_update().
  */
 function entity_test_entity_update(EntityInterface $entity) {
-  \Drupal::state()->set('entity_test.previous', $entity->previous);
+  $previous = null;
+  if (isset($entity->previous)) {
+    $previous = $entity->previous;
+  }
+  \Drupal::state()->set('entity_test.previous', $previous);
 }
 
 /**