diff --git a/core/modules/config/src/Form/ConfigSync.php b/core/modules/config/src/Form/ConfigSync.php
index 7c48dd5..af03103 100644
--- a/core/modules/config/src/Form/ConfigSync.php
+++ b/core/modules/config/src/Form/ConfigSync.php
@@ -36,18 +36,25 @@ class ConfigSync extends FormBase {
   protected $lock;
 
   /**
-   * The source configuration object.
+   * The staging configuration object.
    *
    * @var \Drupal\Core\Config\StorageInterface
    */
-  protected $sourceStorage;
+  protected $stagingStorage;
 
   /**
-   * The target configuration object.
+   * The active configuration object.
    *
    * @var \Drupal\Core\Config\StorageInterface
    */
-  protected $targetStorage;
+  protected $activeStorage;
+
+  /**
+   * The snapshot configuration object.
+   *
+   * @var \Drupal\Core\Config\StorageInterface
+   */
+  protected $snapshotStorage;
 
   /**
    * Event dispatcher.
@@ -94,9 +101,11 @@ class ConfigSync extends FormBase {
   /**
    * Constructs the object.
    *
-   * @param \Drupal\Core\Config\StorageInterface $sourceStorage
+   * @param \Drupal\Core\Config\StorageInterface $staging_storage
    *   The source storage object.
-   * @param \Drupal\Core\Config\StorageInterface $targetStorage
+   * @param \Drupal\Core\Config\StorageInterface $active_storage
+   *   The target storage manager.
+   * @param \Drupal\Core\Config\StorageInterface $snapshot_storage
    *   The target storage manager.
    * @param \Drupal\Core\Lock\LockBackendInterface $lock
    *   The lock object.
@@ -113,9 +122,10 @@ class ConfigSync extends FormBase {
    * @param \Drupal\Core\Extension\ThemeHandlerInterface $theme_handler
    *   The theme handler
    */
-  public function __construct(StorageInterface $sourceStorage, StorageInterface $targetStorage, LockBackendInterface $lock, EventDispatcherInterface $event_dispatcher, ConfigManagerInterface $config_manager, UrlGeneratorInterface $url_generator, TypedConfigManagerInterface $typed_config, ModuleHandlerInterface $module_handler, ThemeHandlerInterface $theme_handler) {
-    $this->sourceStorage = $sourceStorage;
-    $this->targetStorage = $targetStorage;
+  public function __construct(StorageInterface $staging_storage, StorageInterface $active_storage, StorageInterface $snapshot_storage, LockBackendInterface $lock, EventDispatcherInterface $event_dispatcher, ConfigManagerInterface $config_manager, UrlGeneratorInterface $url_generator, TypedConfigManagerInterface $typed_config, ModuleHandlerInterface $module_handler, ThemeHandlerInterface $theme_handler) {
+    $this->stagingStorage = $staging_storage;
+    $this->activeStorage = $active_storage;
+    $this->snapshotStorage = $snapshot_storage;
     $this->lock = $lock;
     $this->eventDispatcher = $event_dispatcher;
     $this->configManager = $config_manager;
@@ -132,6 +142,7 @@ public static function create(ContainerInterface $container) {
     return new static(
       $container->get('config.storage.staging'),
       $container->get('config.storage'),
+      $container->get('config.storage.snapshot'),
       $container->get('lock'),
       $container->get('event_dispatcher'),
       $container->get('config.manager'),
@@ -153,14 +164,18 @@ public function getFormId() {
    * {@inheritdoc}
    */
   public function buildForm(array $form, array &$form_state) {
+    $snapshot_comparer = new StorageComparer($this->activeStorage, $this->snapshotStorage, $this->configManager);
+    if (empty($form_state['input']) && $snapshot_comparer->createChangelist()->hasChanges()) {
+      drupal_set_message($this->t('Changes have been made to your active configuration, which might be lost on the next synchronization.'), 'warning');
+    }
     $form['actions'] = array('#type' => 'actions');
     $form['actions']['submit'] = array(
       '#type' => 'submit',
       '#value' => $this->t('Import all'),
     );
 
-    $source_list = $this->sourceStorage->listAll();
-    $storage_comparer = new StorageComparer($this->sourceStorage, $this->targetStorage, $this->configManager);
+    $source_list = $this->stagingStorage->listAll();
+    $storage_comparer = new StorageComparer($this->stagingStorage, $this->activeStorage, $this->configManager);
     if (empty($source_list) || !$storage_comparer->createChangelist()->hasChanges()) {
       $form['no_changes'] = array(
         '#type' => 'table',
diff --git a/core/modules/config/src/Tests/ConfigExportImportUITest.php b/core/modules/config/src/Tests/ConfigExportImportUITest.php
index bd0c70f..8b691af 100644
--- a/core/modules/config/src/Tests/ConfigExportImportUITest.php
+++ b/core/modules/config/src/Tests/ConfigExportImportUITest.php
@@ -120,6 +120,17 @@ public function testExportImport() {
 
     $this->drupalGet('node/add');
     $this->assertFieldByName("{$this->field->name}[0][value]", '', 'Widget is displayed');
+
+    \Drupal::config('system.site')
+      ->set('slogan', $this->originalSlogan)
+      ->save();
+    $this->drupalGet('admin/config/development/configuration');
+    $this->assertText('Changes have been made to your active configuration, which might be lost on the next synchronization.');
+    $this->drupalPostForm('admin/config/development/configuration', array(), 'Import all');
+    $this->drupalGet('admin/config/development/configuration');
+    $this->assertNoText(t('Changes have been made to your active configuration, which might be lost on the next synchronization.'));
+    $this->assertText(t('There are no configuration changes.'));
+
   }
 
   /**