diff --git a/core/modules/responsive_image/responsive_image.module b/core/modules/responsive_image/responsive_image.module
index 068f3ea..27c83ca 100644
--- a/core/modules/responsive_image/responsive_image.module
+++ b/core/modules/responsive_image/responsive_image.module
@@ -297,7 +297,7 @@ function template_preprocess_responsive_image(&$variables) {
  * <source media="(min-width:0px)" srcset="img1.jpeg 50w 1x, img2.jpeg=100w 1x" />
  * @endcode
  *
- * Note: Since The specs do not allow width descriptors and multipliers combined
+ * Note: Since the specs do not allow width descriptors and multipliers combined
  * inside one 'srcset' attribute, we either have to use something like
  * @code
  * <source [...] srcset="image1.jpeg 1x, image2.webp 2x, image3.jpeg 3x" />
diff --git a/core/modules/responsive_image/src/Tests/ResponsiveImageFieldUITest.php b/core/modules/responsive_image/src/Tests/ResponsiveImageFieldUITest.php
new file mode 100644
index 0000000..57e2bff
--- /dev/null
+++ b/core/modules/responsive_image/src/Tests/ResponsiveImageFieldUITest.php
@@ -0,0 +1,136 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\responsive_image\Tests\ResponsiveImageFieldUITest.
+ */
+
+namespace Drupal\responsive_image\Tests;
+
+
+use Drupal\field_ui\Tests\FieldUiTestTrait;
+use Drupal\simpletest\WebTestBase;
+
+/**
+ * Tests the "Responsive Image" formatter settings form.
+ *
+ * @group responsive_image
+ */
+class ResponsiveImageFieldUITest extends WebTestBase {
+
+  use FieldUiTestTrait;
+
+  /**
+   * Modules to install.
+   *
+   * @var array
+   */
+  public static $modules = array('node', 'field_ui', 'image', 'responsive_image', 'responsive_image_test_module', 'block');
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+    $this->drupalPlaceBlock('system_breadcrumb_block');
+    // Create a test user.
+    $admin_user = $this->drupalCreateUser(array('access content', 'administer content types', 'administer node fields', 'administer node form display', 'administer node display', 'bypass node access'));
+    $this->drupalLogin($admin_user);
+
+    // Create content type, with underscores.
+    $type_name = strtolower($this->randomMachineName(8)) . '_test';
+    $type = $this->drupalCreateContentType(array('name' => $type_name, 'type' => $type_name));
+    $this->type = $type->id();
+  }
+
+  /**
+   * Tests formatter settings.
+   */
+  function testResponsiveImageFormatterUI() {
+    $manage_fields = 'admin/structure/types/manage/' . $this->type;
+    $manage_display = $manage_fields . '/display';
+
+    // Create a field, and a node with some data for the field.
+    $this->fieldUIAddNewField($manage_fields, 'image', 'Image field', 'image');
+    // Display the "Manage display".
+    $this->drupalGet($manage_display);
+
+    // Change the formatter and check that the summary is updated.
+    $edit = array('fields[field_image][type]' => 'responsive_image', 'refresh_rows' => 'field_image');
+    $this->drupalPostAjaxForm(NULL, $edit, array('op' => t('Refresh')));
+    $this->assertText("Select a responsive image mapping.", 'The expected summary is displayed.');
+
+    // Submit the form.
+    $this->drupalPostForm(NULL, array(), t('Save'));
+    $this->assertText("Select a responsive image mapping.", 'The expected summary is displayed.');
+
+    // Create responsive image mappings.
+    $responsive_image_mapping = entity_create('responsive_image_mapping', array(
+      'id' => 'mapping_one',
+      'label' => 'Mapping One',
+      'breakpoint_group' => 'responsive_image_test_module',
+    ));
+    $responsive_image_mapping
+      ->addMappingDefinition('responsive_image_test_module.mobile', '1x', array(
+        'image_mapping_type' => 'image_style',
+        'image_mapping' => 'thumbnail',
+      ))
+      ->addMappingDefinition('responsive_image_test_module.narrow', '1x', array(
+        'image_mapping_type' => 'image_style',
+        'image_mapping' => 'medium'
+      ))
+      // Test the normal output of mapping to an image style.
+      ->addMappingDefinition('responsive_image_test_module.wide', '1x', array(
+        'image_mapping_type' => 'image_style',
+        'image_mapping' => 'large',
+      ))
+      ->save();
+    \Drupal::entityManager()->clearCachedFieldDefinitions();
+    // Refresh the page.
+    $this->drupalGet($manage_display);
+    $this->assertText("Select a responsive image mapping.", 'The expected summary is displayed.');
+
+    // Click on the formatter settings button to open the formatter settings
+    // form.
+    $this->drupalPostAjaxForm(NULL, array(), "field_image_settings_edit");
+
+    // Assert that the correct fields are present.
+    $fieldnames = array(
+      'fields[field_image][settings_edit_form][settings][responsive_image_mapping]',
+      'fields[field_image][settings_edit_form][settings][fallback_image_style]',
+      'fields[field_image][settings_edit_form][settings][image_link]',
+    );
+    foreach ($fieldnames as $fieldname) {
+      $this->assertField($fieldname);
+    }
+    $edit = array(
+      'fields[field_image][settings_edit_form][settings][responsive_image_mapping]' => 'mapping_one',
+      'fields[field_image][settings_edit_form][settings][fallback_image_style]' => 'thumbnail',
+      'fields[field_image][settings_edit_form][settings][image_link]' => 'content',
+    );
+    $this->drupalPostAjaxForm(NULL, $edit, "field_image_plugin_settings_update");
+
+    // Save the form to save the settings.
+    $this->drupalPostForm(NULL, array(), t('Save'));
+    $this->assertText('Responsive image mapping: Mapping One');
+    $this->assertText('Fallback Image style: Thumbnail (100×100)');
+    $this->assertText('Linked to content');
+
+    // Click on the formatter settings button to open the formatter settings
+    // form.
+    $this->drupalPostAjaxForm(NULL, array(), "field_image_settings_edit");
+    $edit = array(
+      'fields[field_image][settings_edit_form][settings][responsive_image_mapping]' => 'mapping_one',
+      'fields[field_image][settings_edit_form][settings][fallback_image_style]' => '',
+      'fields[field_image][settings_edit_form][settings][image_link]' => 'file',
+    );
+    $this->drupalPostAjaxForm(NULL, $edit, "field_image_plugin_settings_update");
+
+    // Save the form to save the third party settings.
+    $this->drupalPostForm(NULL, array(), t('Save'));
+    $this->assertText('Responsive image mapping: Mapping One');
+    $this->assertText('Automatic fallback');
+    $this->assertText('Linked to file');
+  }
+
+}