diff --git a/src/Plugin/Field/FieldType/DynamicEntityReferenceItem.php b/src/Plugin/Field/FieldType/DynamicEntityReferenceItem.php
index d71c201..43c2a5a 100644
--- a/src/Plugin/Field/FieldType/DynamicEntityReferenceItem.php
+++ b/src/Plugin/Field/FieldType/DynamicEntityReferenceItem.php
@@ -215,7 +215,7 @@ class DynamicEntityReferenceItem extends EntityReferenceItem {
    * Returns a form for single target type settings.
    *
    * This is same as
-   * \Drupal\entity_reference\ConfigurableEntityReferenceItem::fieldSettingsForm()
+   * \Drupal\Core\Field\Plugin\Field\FieldType\EntityReferenceItem::fieldSettingsForm()
    * but it uses dynamic_entity_reference_selection plugin manager instead of
    * entity_reference_selection plugin manager.
    *
@@ -253,8 +253,8 @@ class DynamicEntityReferenceItem extends EntityReferenceItem {
 
     $form = array(
       '#type' => 'container',
-      '#process' => array(array(get_class($this), 'fieldSettingsAjaxProcess')),
-      '#element_validate' => array(array(get_class($this), 'fieldSettingsFormValidate')),
+      '#process' => [[EntityReferenceItem::class, 'fieldSettingsAjaxProcess']],
+      '#element_validate' => [[DynamicEntityReferenceItem::class, 'fieldSettingsFormValidate']],
     );
     $form['handler'] = array(
       '#type' => 'details',
@@ -303,20 +303,40 @@ class DynamicEntityReferenceItem extends EntityReferenceItem {
    *   The form state of the (entire) configuration form.
    */
   public static function fieldSettingsFormValidate(array $form, FormStateInterface $form_state) {
-    if ($form_state->hasValue('field')) {
-      $settings = $form_state->getValue(array('field', 'settings'));
-      foreach (array_keys($settings) as $target_type) {
-        $form_state->unsetValue(array(
-          'field',
+    /** @var \Drupal\field\Entity\FieldConfig $field */
+    $field = $form_state->getFormObject()->getEntity();
+    foreach (static::getTargetTypes($field->getSettings()) as $target_type) {
+      // If no checkboxes were checked for 'target_bundles', store NULL ("all
+      // bundles are referenceable") rather than empty array ("no bundle is
+      // referenceable" - typically happens when all referenceable bundles have
+      // been deleted).
+      if ($form_state->getValue([
+        'settings',
+        $target_type,
+        'handler_settings',
+        'target_bundles',
+      ]) === []) {
+        $form_state->setValue([
           'settings',
           $target_type,
-          'handler_submit',
-        ));
-        /** @var \Drupal\Core\Entity\EntityReferenceSelection\SelectionInterface $handler */
-        $handler = \Drupal::service('plugin.manager.dynamic_entity_reference_selection')->getSelectionHandler($form_state->get('field'), NULL, $target_type);
-        $handler->validateConfigurationForm($form, $form_state);
+          'handler_settings',
+          'target_bundles',
+        ], NULL);
       }
-      $form_state->get('field')->settings = $form_state->getValue(array('field', 'settings'));
+      // Don't store the 'target_bundles_update' button value into the field
+      // config settings.
+      $form_state->unsetValue([
+        'settings',
+        $target_type,
+        'handler_settings',
+        'target_bundles_update',
+      ]);
+      $form_state->unsetValue([
+        'settings',
+        $target_type,
+        'handler_submit',
+      ]);
+
     }
   }
 
diff --git a/tests/src/FunctionalJavascript/DynamicEntityReferenceTest.php b/tests/src/FunctionalJavascript/DynamicEntityReferenceTest.php
new file mode 100644
index 0000000..ac9de27
--- /dev/null
+++ b/tests/src/FunctionalJavascript/DynamicEntityReferenceTest.php
@@ -0,0 +1,136 @@
+<?php
+
+namespace Drupal\Tests\dynamic_entity_reference\FunctionalJavascript;
+
+use Behat\Mink\Exception\ElementNotFoundException;
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
+use Drupal\entity_test\Entity\EntityTestBundle;
+use Drupal\FunctionalJavascriptTests\JavascriptTestBase;
+
+/**
+ * Ensures that Dynamic Entity References field works correctly.
+ *
+ * @group dynamic_entity_reference
+ */
+class DynamicEntityReferenceTest extends JavascriptTestBase {
+
+  /**
+   * The admin user.
+   *
+   * @var \Drupal\user\Entity\User
+   */
+  protected $adminUser;
+
+  /**
+   * The another user.
+   *
+   * @var \Drupal\user\Entity\User
+   */
+  protected $anotherUser;
+
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = [
+    'entity_reference',
+    'field_ui',
+    'dynamic_entity_reference',
+    'entity_test',
+  ];
+
+  /**
+   * Permissions to grant admin user.
+   *
+   * @var array
+   */
+  protected $permissions = [
+    'access administration pages',
+    'view test entity',
+    'administer entity_test fields',
+    'administer entity_test content',
+    'access user profiles',
+  ];
+
+  /**
+   * Sets the test up.
+   */
+  protected function setUp() {
+    parent::setUp();
+    $this->adminUser = $this->drupalCreateUser($this->permissions);
+    $this->anotherUser = $this->drupalCreateUser();
+  }
+
+  /**
+   * Tests if the toolbar can be toggled with JavaScript.
+   */
+  public function testFieldSettings() {
+    $assert_session = $this->assertSession();
+    // Add EntityTestBundle for EntityTestWithBundle.
+    EntityTestBundle::create([
+      'id' => 'test',
+      'label' => 'Test label',
+      'description' => 'My test description',
+    ])->save();
+    $this->drupalLogin($this->adminUser);
+    // Add a new dynamic entity reference field.
+    $this->drupalGet('entity_test/structure/entity_test/fields/add-field');
+    $edit = [
+      'label' => 'Foobar',
+      'field_name' => 'foobar',
+      'new_storage_type' => 'dynamic_entity_reference',
+    ];
+    $this->submitForm($edit, t('Save and continue'), 'field-ui-field-storage-add-form');
+    $page = $this->getSession()->getPage();
+    $assert_session->selectExists('settings[entity_type_ids][]', $page)
+      ->selectOption('user');
+    $assert_session->selectExists('cardinality', $page)
+      ->selectOption(FieldStorageDefinitionInterface::CARDINALITY_UNLIMITED);
+    $this->submitForm([], t('Save field settings'), 'field-storage-config-edit-form');
+    $target_type_select = $assert_session->selectExists('default_value_input[field_foobar][0][target_type]');
+    $target_type_select->selectOption('entity_test');
+    try {
+      $target_type_select->selectOption('user');
+    }
+    catch (ElementNotFoundException $e) {
+      $this->assertTrue(TRUE, 'Entity type select doesn\'t have "user" option.');
+    }
+    $edit = [
+      'settings[entity_test_label][handler_settings][target_bundles][entity_test_label]' => TRUE,
+      'settings[entity_test_view_builder][handler_settings][target_bundles][entity_test_view_builder]' => TRUE,
+      'settings[entity_test_no_id][handler_settings][target_bundles][entity_test_no_id]' => TRUE,
+      'settings[entity_test_no_label][handler_settings][target_bundles][entity_test_no_label]' => TRUE,
+      'settings[entity_test_label_callback][handler_settings][target_bundles][entity_test_label_callback]' => TRUE,
+      'settings[entity_test][handler_settings][target_bundles][entity_test]' => TRUE,
+      'settings[entity_test_admin_routes][handler_settings][target_bundles][entity_test_admin_routes]' => TRUE,
+      'settings[entity_test_base_field_display][handler_settings][target_bundles][entity_test_base_field_display]' => TRUE,
+      'settings[entity_test_mul][handler_settings][target_bundles][entity_test_mul]' => TRUE,
+      'settings[entity_test_mul_changed][handler_settings][target_bundles][entity_test_mul_changed]' => TRUE,
+      'settings[entity_test_mul_default_value][handler_settings][target_bundles][entity_test_mul_default_value]' => TRUE,
+      'settings[entity_test_mul_langcode_key][handler_settings][target_bundles][entity_test_mul_langcode_key]' => TRUE,
+      'settings[entity_test_rev][handler_settings][target_bundles][entity_test_rev]' => TRUE,
+      'settings[entity_test_mulrev_changed][handler_settings][target_bundles][entity_test_mulrev_changed]' => TRUE,
+      'settings[entity_test_mulrev][handler_settings][target_bundles][entity_test_mulrev]' => TRUE,
+      'settings[entity_test_revlog][handler_settings][target_bundles][entity_test_revlog]' => TRUE,
+      'settings[entity_test_constraints][handler_settings][target_bundles][entity_test_constraints]' => TRUE,
+      'settings[entity_test_composite_constraint][handler_settings][target_bundles][entity_test_composite_constraint]' => TRUE,
+      'settings[entity_test_constraint_violation][handler_settings][target_bundles][entity_test_constraint_violation]' => TRUE,
+      'settings[entity_test_field_override][handler_settings][target_bundles][entity_test_field_override]' => TRUE,
+      'settings[entity_test_default_value][handler_settings][target_bundles][entity_test_default_value]' => TRUE,
+      'settings[entity_test_update][handler_settings][target_bundles][entity_test_update]' => TRUE,
+      'settings[entity_test_with_bundle][handler_settings][target_bundles][test]' => TRUE,
+      'settings[entity_test_default_access][handler_settings][target_bundles][entity_test_default_access]' => TRUE,
+      'settings[entity_test_cache][handler_settings][target_bundles][entity_test_cache]' => TRUE,
+      'settings[entity_test_string_id][handler_settings][target_bundles][entity_test_string_id]' => TRUE,
+    ];
+    $page = $this->getSession()->getPage();
+    foreach (array_keys($edit) as $checkbox) {
+      $page->checkField($checkbox);
+      $this->assertJsCondition('(typeof(jQuery)=="undefined" || (0 === jQuery.active && 0 === jQuery(\':animated\').length))');
+    }
+    $this->submitForm([], t('Save settings'), 'field-config-edit-form');
+    $assert_session->pageTextContains((string) t('Saved %name configuration', array('%name' => 'Foobar')));
+  }
+
+}