diff --git a/core/modules/config/src/Tests/ConfigEntityFormOverrideTest.php b/core/modules/config/src/Tests/ConfigEntityFormOverrideTest.php
index a07da59..632d2dc 100644
--- a/core/modules/config/src/Tests/ConfigEntityFormOverrideTest.php
+++ b/core/modules/config/src/Tests/ConfigEntityFormOverrideTest.php
@@ -31,6 +31,8 @@ public function testFormsWithOverrides() {
     $overridden_label = 'Overridden label';
     $edited_label = 'Edited label';
 
+    $config_test_storage = $this->container->get('entity.manager')->getStorage('config_test');
+
     // Set up an override.
     $settings['config']['config_test.dynamic.dotted.default']['label'] = (object) array(
       'value' => $overridden_label,
@@ -39,7 +41,7 @@ public function testFormsWithOverrides() {
     $this->writeSettings($settings);
 
     // Test that the overridden label is loaded with the entity.
-    $this->assertEqual(config_test_load('dotted.default')->label(), $overridden_label);
+    $this->assertEqual($config_test_storage->load('dotted.default')->label(), $overridden_label);
 
     // Test that the original label on the listing page is intact.
     $this->drupalGet('admin/structure/config_test');
@@ -67,7 +69,7 @@ public function testFormsWithOverrides() {
     $this->assertIdentical((string) $elements[0]['value'], $edited_label);
 
     // Test that the overridden label is still loaded with the entity.
-    $this->assertEqual(config_test_load('dotted.default')->label(), $overridden_label);
+    $this->assertEqual($config_test_storage->load('dotted.default')->label(), $overridden_label);
   }
 
 }
diff --git a/core/modules/config/tests/config_test/config_test.module b/core/modules/config/tests/config_test/config_test.module
index c17d688..9510aba 100644
--- a/core/modules/config/tests/config_test/config_test.module
+++ b/core/modules/config/tests/config_test/config_test.module
@@ -11,16 +11,6 @@
 require_once dirname(__FILE__) . '/config_test.hooks.inc';
 
 /**
- * Loads a ConfigTest object.
- *
- * @param string $id
- *   The ID of the ConfigTest object to load.
- */
-function config_test_load($id) {
-  return entity_load('config_test', $id);
-}
-
-/**
  * Implements hook_cache_flush().
  */
 function config_test_cache_flush() {
diff --git a/core/modules/config/tests/config_test/src/ConfigTestForm.php b/core/modules/config/tests/config_test/src/ConfigTestForm.php
index 0967206..ac0bb17 100644
--- a/core/modules/config/tests/config_test/src/ConfigTestForm.php
+++ b/core/modules/config/tests/config_test/src/ConfigTestForm.php
@@ -8,7 +8,9 @@
 namespace Drupal\config_test;
 
 use Drupal\Core\Entity\EntityForm;
+use Drupal\Core\Entity\Query\QueryFactory;
 use Drupal\Core\Form\FormStateInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
  * Form controller for the test config edit forms.
@@ -16,6 +18,32 @@
 class ConfigTestForm extends EntityForm {
 
   /**
+   * The entity query.
+   *
+   * @var \Drupal\Core\Entity\Query\QueryFactory
+   */
+  protected $entityQuery;
+
+  /**
+   * Constructs a new ConfigTestForm.
+   *
+   * @param \Drupal\Core\Entity\Query\QueryFactory $entity_query
+   *   The entity query.
+   */
+  public function __construct(QueryFactory $entity_query) {
+    $this->entityQuery = $entity_query;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static(
+      $container->get('entity.query')
+    );
+  }
+
+  /**
    * {@inheritdoc}
    */
   public function form(array $form, FormStateInterface $form_state) {
@@ -33,7 +61,7 @@ public function form(array $form, FormStateInterface $form_state) {
       '#default_value' => $entity->id(),
       '#required' => TRUE,
       '#machine_name' => array(
-        'exists' => 'config_test_load',
+        'exists' => [$this, 'exists'],
         'replace_pattern' => '[^a-z0-9_.]+',
       ),
     );
@@ -142,4 +170,25 @@ public function save(array $form, FormStateInterface $form_state) {
     $form_state->setRedirectUrl($this->entity->urlInfo('collection'));
   }
 
+  /**
+   * Determines if the entity already exists.
+   *
+   * @param string|int $entity_id
+   *   The entity ID.
+   * @param array $element
+   *   The form element.
+   * @param \Drupal\Core\Form\FormStateInterface $form_state
+   *   The current state of the form.
+   *
+   * @return bool
+   *   TRUE if the entity exists, FALSE otherwise.
+   */
+  public function exists($entity_id, array $element, FormStateInterface $form_state) {
+    /** @var \Drupal\Core\Config\Entity\ConfigEntityInterface $entity */
+    $entity = $form_state->getFormObject()->getEntity();
+    return (bool) $this->entityQuery->get($entity->getEntityTypeId())
+      ->condition($entity->getEntityType()->getKey('id'), $entity_id)
+      ->execute();
+  }
+
 }
diff --git a/core/modules/config_translation/src/Tests/ConfigTranslationOverviewTest.php b/core/modules/config_translation/src/Tests/ConfigTranslationOverviewTest.php
index 4c83a38..0916dcd 100644
--- a/core/modules/config_translation/src/Tests/ConfigTranslationOverviewTest.php
+++ b/core/modules/config_translation/src/Tests/ConfigTranslationOverviewTest.php
@@ -153,6 +153,8 @@ public function testListingPageWithOverrides() {
     $original_label = 'Default';
     $overridden_label = 'Overridden label';
 
+    $config_test_storage = $this->container->get('entity.manager')->getStorage('config_test');
+
     // Set up an override.
     $settings['config']['config_test.dynamic.dotted.default']['label'] = (object) array(
       'value' => $overridden_label,
@@ -161,7 +163,7 @@ public function testListingPageWithOverrides() {
     $this->writeSettings($settings);
 
     // Test that the overridden label is loaded with the entity.
-    $this->assertEqual(config_test_load('dotted.default')->label(), $overridden_label);
+    $this->assertEqual($config_test_storage->load('dotted.default')->label(), $overridden_label);
 
     // Test that the original label on the listing page is intact.
     $this->drupalGet('admin/config/regional/config-translation/config_test');