.../Core/Entity/Entity/EntityFormDisplay.php       |  6 +++---
 .../user/src/Tests/UserRegistrationTest.php        | 24 +++++++++++++---------
 2 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/core/lib/Drupal/Core/Entity/Entity/EntityFormDisplay.php b/core/lib/Drupal/Core/Entity/Entity/EntityFormDisplay.php
index abb00d9..c864ceb 100644
--- a/core/lib/Drupal/Core/Entity/Entity/EntityFormDisplay.php
+++ b/core/lib/Drupal/Core/Entity/Entity/EntityFormDisplay.php
@@ -8,11 +8,11 @@
 namespace Drupal\Core\Entity\Entity;
 
 use Drupal\Core\Cache\Cache;
+use Drupal\Core\Config\Entity\ConfigEntityInterface;
 use Drupal\Core\Entity\EntityDisplayPluginCollection;
 use Drupal\Core\Entity\FieldableEntityInterface;
 use Drupal\Core\Entity\Display\EntityFormDisplayInterface;
 use Drupal\Core\Entity\EntityDisplayBase;
-use Drupal\Core\Field\FieldConfigInterface;
 use Drupal\Core\Form\FormStateInterface;
 
 /**
@@ -171,11 +171,11 @@ public function buildForm(FieldableEntityInterface $entity, array &$form, FormSt
         // Associate the cache tags for the field definition & field storage
         // definition.
         $field_definition = $this->getFieldDefinition($name);
-        if ($field_definition instanceof FieldConfigInterface) {
+        if ($field_definition instanceof ConfigEntityInterface) {
           // @todo: Use RendererInterface::addDependency() once https://www.drupal.org/node/2444231 lands.
           $form['name']['#cache']['tags'] = $field_definition->getCacheTags();
           $field_storage_definition = $field_definition->getFieldStorageDefinition();
-          if ($field_storage_definition instanceof FieldConfigInterface) {
+          if ($field_storage_definition instanceof ConfigEntityInterface) {
             $form['name']['#cache']['tags'] = Cache::mergeTags($form['name']['#cache']['tags'], $field_storage_definition->getCacheTags());
           }
         }
diff --git a/core/modules/user/src/Tests/UserRegistrationTest.php b/core/modules/user/src/Tests/UserRegistrationTest.php
index 24e6972..ff3fa30 100644
--- a/core/modules/user/src/Tests/UserRegistrationTest.php
+++ b/core/modules/user/src/Tests/UserRegistrationTest.php
@@ -227,16 +227,10 @@ function testRegistrationWithUserFields() {
     entity_get_form_display('user', 'user', 'register')
       ->setComponent('test_user_field', array('type' => 'test_field_widget'))
       ->save();
-    $check_cache_tags = function() {
-      $this->assertCacheTag('config:core.entity_form_display.user.user.register');
-      $this->assertCacheTag('config:field.field.user.user.test_user_field');
-      $this->assertCacheTag('config:field.storage.user.test_user_field');
-      $this->assertCacheTag('config:user.settings');
-    };
 
     $this->drupalGet('user/register');
     $this->assertText($field->label(), 'The field appears on user registration form');
-    $check_cache_tags();
+    $this->assertRegistrationFormCacheTagsWithUserFields();
 
     // Check that validation errors are correctly reported.
     $edit = array();
@@ -245,12 +239,12 @@ function testRegistrationWithUserFields() {
     // Missing input in required field.
     $edit['test_user_field[0][value]'] = '';
     $this->drupalPostForm(NULL, $edit, t('Create new account'));
-    $check_cache_tags();
+    $this->assertRegistrationFormCacheTagsWithUserFields();
     $this->assertRaw(t('@name field is required.', array('@name' => $field->label())), 'Field validation error was correctly reported.');
     // Invalid input.
     $edit['test_user_field[0][value]'] = '-1';
     $this->drupalPostForm(NULL, $edit, t('Create new account'));
-    $check_cache_tags();
+    $this->assertRegistrationFormCacheTagsWithUserFields();
     $this->assertRaw(t('%name does not accept the value -1.', array('%name' => $field->label())), 'Field validation error was correctly reported.');
 
     // Submit with valid data.
@@ -267,7 +261,7 @@ function testRegistrationWithUserFields() {
     $field_storage->save();
     foreach (array('js', 'nojs') as $js) {
       $this->drupalGet('user/register');
-      $check_cache_tags();
+      $this->assertRegistrationFormCacheTagsWithUserFields();
       // Add two inputs.
       $value = rand(1, 255);
       $edit = array();
@@ -295,4 +289,14 @@ function testRegistrationWithUserFields() {
     }
   }
 
+  /**
+   * Asserts the presence of cache tags on registration form with user fields.
+   */
+  protected function assertRegistrationFormCacheTagsWithUserFields() {
+    $this->assertCacheTag('config:core.entity_form_display.user.user.register');
+    $this->assertCacheTag('config:field.field.user.user.test_user_field');
+    $this->assertCacheTag('config:field.storage.user.test_user_field');
+    $this->assertCacheTag('config:user.settings');
+  }
+
 }