diff --git a/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTest.php b/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTest.php
index 947c027..1bef99c 100644
--- a/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTest.php
+++ b/core/modules/config/lib/Drupal/config/Tests/ConfigSchemaTest.php
@@ -7,6 +7,8 @@
 
 namespace Drupal\config\Tests;
 
+use Drupal\Core\Config\FileStorage;
+use Drupal\Core\Config\InstallStorage;
 use Drupal\Core\TypedData\Type\IntegerInterface;
 use Drupal\Core\TypedData\Type\StringInterface;
 use Drupal\simpletest\DrupalUnitTestBase;
@@ -334,6 +336,14 @@ public function testConfigSaveWithSchema() {
       ->setData($untyped_values)
       ->save();
     $this->assertIdentical(\Drupal::config('config_schema_test.no_schema_data_types')->get(), $untyped_values);
+
+    // Ensure that configuration objects with keys marked as ignored are not
+    // changed when saved. The 'config_schema_test.ignore' will have been saved
+    // during the installation of configuration in the setUp method.
+    $extension_path = drupal_get_path('module', 'config_schema_test');
+    $install_storage = new FileStorage($extension_path . '/' . InstallStorage::CONFIG_INSTALL_DIRECTORY);
+    $original_data = $install_storage->read('config_schema_test.ignore');
+    $this->assertIdentical(\Drupal::config('config_schema_test.ignore')->get(), $original_data);
   }
 
   /**