diff --git a/core/lib/Drupal/Core/Entity/Plugin/EntityReferenceSelection/SelectionBase.php b/core/lib/Drupal/Core/Entity/Plugin/EntityReferenceSelection/SelectionBase.php
index c2e91c2..f6c374f 100644
--- a/core/lib/Drupal/Core/Entity/Plugin/EntityReferenceSelection/SelectionBase.php
+++ b/core/lib/Drupal/Core/Entity/Plugin/EntityReferenceSelection/SelectionBase.php
@@ -243,6 +243,8 @@ public function buildConfigurationForm(array $form, FormStateInterface $form_sta
    * {@inheritdoc}
    */
   public function validateConfigurationForm(array &$form, FormStateInterface $form_state) {
+    // Don't store the 'target_bundles_update' button value into the field
+    // config settings.
     $form_state->unsetValue(['field', 'settings', 'handler_settings', 'target_bundles_update']);
   }
 
diff --git a/core/modules/entity_reference/src/Tests/EntityReferenceAdminTest.php b/core/modules/entity_reference/src/Tests/EntityReferenceAdminTest.php
index 7b5a554..4616bb2 100644
--- a/core/modules/entity_reference/src/Tests/EntityReferenceAdminTest.php
+++ b/core/modules/entity_reference/src/Tests/EntityReferenceAdminTest.php
@@ -223,10 +223,10 @@ public function testAvailableFormatters() {
   }
 
   /**
-   * Tests field settings for taxonomy term entity reference field when the
-   * field is set to auto-create the target term in more than one vocabularies.
+   * Tests field settings for an entity reference field when the field has
+   * multiple target bundles and is set to auto-create the target entity.
    */
-  public function testMultipleTargetTaxonomyVocabularies() {
+  public function testMultipleTargetBundles() {
     /** @var \Drupal\taxonomy\Entity\Vocabulary[] $vocabularies */
     $vocabularies = [];
     for ($i = 0; $i < 2; $i++) {
diff --git a/core/modules/entity_reference/src/Tests/EntityReferenceAutoCreateTest.php b/core/modules/entity_reference/src/Tests/EntityReferenceAutoCreateTest.php
index a9b389f..69f6491 100644
--- a/core/modules/entity_reference/src/Tests/EntityReferenceAutoCreateTest.php
+++ b/core/modules/entity_reference/src/Tests/EntityReferenceAutoCreateTest.php
@@ -10,7 +10,6 @@
 use Drupal\Component\Utility\Unicode;
 use Drupal\Core\Field\FieldStorageDefinitionInterface;
 use Drupal\field\Entity\FieldConfig;
-use Drupal\field\Entity\FieldStorageConfig;
 use Drupal\taxonomy\Entity\Vocabulary;
 use Drupal\simpletest\WebTestBase;
 use Drupal\node\Entity\Node;
@@ -22,6 +21,8 @@
  */
 class EntityReferenceAutoCreateTest extends WebTestBase {
 
+  use EntityReferenceTestTrait;
+
   public static $modules = ['entity_reference', 'node', 'taxonomy'];
 
   /**
@@ -140,10 +141,10 @@ public function testAutoCreate() {
   }
 
   /**
-   * Tests if a taxonomy term entity reference field having multiple target
-   * vocabularies is storing the term in the right destination.
+   * Tests if a entity reference field having multiple target bundles is storing
+   * the auto-created entity in the right destination.
    */
-  public function testMultipleTargetTaxonomyVocabularies() {
+  public function testMultipleTargetBundles() {
     /** @var \Drupal\taxonomy\Entity\Vocabulary[] $vocabularies */
     $vocabularies = [];
     for ($i = 0; $i < 2; $i++) {
@@ -159,31 +160,16 @@ public function testMultipleTargetTaxonomyVocabularies() {
     // taxonomy terms in the second vocabulary from the two that were configured
     // as targets.
     $field_name = Unicode::strtolower($this->randomMachineName());
-    FieldStorageConfig::create([
-      'field_name' => $field_name,
-      'entity_type' => 'node',
-      'settings' => array(
-        'target_type' => 'taxonomy_term',
-      ),
-      'type' => 'entity_reference',
-    ])->save();
-    FieldConfig::create([
-      'label' => $this->randomMachineName(),
-      'entity_type' => 'node',
-      'bundle' => $this->referencingType,
-      'field_name' => $field_name,
-      'settings' => [
-        'handler' => 'default',
-        'handler_settings' => [
-          'target_bundles' => [
-            $vocabularies[0]->id() => $vocabularies[0]->id(),
-            $vocabularies[1]->id() => $vocabularies[1]->id(),
-          ],
-          'auto_create' => TRUE,
-          'auto_create_bundle' => $vocabularies[1]->id(),
-        ],
+    $handler_settings = [
+      'target_bundles' => [
+        $vocabularies[0]->id() => $vocabularies[0]->id(),
+        $vocabularies[1]->id() => $vocabularies[1]->id(),
       ],
-    ])->save();
+      'auto_create' => TRUE,
+      'auto_create_bundle' => $vocabularies[1]->id(),
+    ];
+    $this->createEntityReferenceField('node', $this->referencingType, $field_name, $this->randomString(), 'taxonomy_term', 'default', $handler_settings);
+    /** @var \Drupal\Core\Entity\Display\EntityFormDisplayInterface $fd */
     entity_get_form_display('node', $this->referencingType, 'default')
       ->setComponent($field_name, ['type' => 'entity_reference_autocomplete'])
       ->save();
@@ -222,6 +208,26 @@ public function testMultipleTargetTaxonomyVocabularies() {
 
     // The second term is expected to be stored in the first vocabulary.
     $this->assertEqual($vocabularies[0]->id(), $term->bundle());
+
+    // Test the case when the field config settings are inconsistent.
+    unset($field_config->settings['handler_settings']['auto_create_bundle']);
+    $field_config->save();
+
+    // If we use $this->drupalGet() we cannot catch the exception because the
+    // form builder runs in other PHP space. Instead we are only building the
+    // form in order to check if the exception is thrown.
+    try {
+      /** @var \Drupal\Core\Form\FormBuilderInterface $form_builder */
+      $form_builder = $this->container->get('entity.form_builder');
+      $form_builder->getForm(Node::load(1));
+      $this->fail("Missed 'auto_create_bundle' should throw \\InvalidArgumentException but it didn't.");
+    }
+    catch (\InvalidArgumentException $e) {
+      $this->assertIdentical(
+        $e->getMessage(),
+        "Reference auto-create is enabled on multiple target bundles but 'auto_create_bundle' is not set."
+      );
+    }
   }
 
 }