diff --git a/core/modules/config/src/Tests/ConfigEntityStorageTest.php b/core/modules/config/src/Tests/ConfigEntityStorageTest.php
index dea998b..55b06ed 100644
--- a/core/modules/config/src/Tests/ConfigEntityStorageTest.php
+++ b/core/modules/config/src/Tests/ConfigEntityStorageTest.php
@@ -54,4 +54,15 @@ public function testUUIDConflict() {
     $this->assertIdentical($entity->toArray(), $original_properties);
   }
 
+  public function testToArray() {
+    $entity_type = 'config_test';
+    $id = 'test_1';
+    // Load the original configuration entity.
+    entity_create($entity_type, ['id' => $id, 'protected_property' => 'TEST'])->save();
+    $entity = entity_load($entity_type, $id);
+
+    $array = $entity->toArray();
+    $this->assertEqual($array['protected_property'], 'TEST', 'Found protected Property on newly created entity.');
+  }
+
 }
diff --git a/core/modules/config/tests/config_test/src/Entity/ConfigTest.php b/core/modules/config/tests/config_test/src/Entity/ConfigTest.php
index 8ad8262..9fb6ca5 100644
--- a/core/modules/config/tests/config_test/src/Entity/ConfigTest.php
+++ b/core/modules/config/tests/config_test/src/Entity/ConfigTest.php
@@ -31,7 +31,8 @@
  *   entity_keys = {
  *     "id" = "id",
  *     "label" = "label",
- *     "status" = "status"
+ *     "status" = "status",
+ *     "protectedProperty" = "protected_property",
  *   },
  *   links = {
  *     "edit-form" = "/admin/structure/config_test/manage/{config_test}",
@@ -77,7 +78,7 @@ class ConfigTest extends ConfigEntityBase implements ConfigTestInterface {
    *
    * @var string
    */
-  protected $protected_property;
+  protected $protectedProperty;
 
   /**
    * {@inheritdoc}