diff --git a/core/modules/locale/src/Tests/LocaleConfigTranslationTest.php b/core/modules/locale/src/Tests/LocaleConfigTranslationTest.php
index d5a7c21..96931ae 100644
--- a/core/modules/locale/src/Tests/LocaleConfigTranslationTest.php
+++ b/core/modules/locale/src/Tests/LocaleConfigTranslationTest.php
@@ -18,6 +18,13 @@
 class LocaleConfigTranslationTest extends WebTestBase {
 
   /**
+   * The language code used.
+   *
+   * @var string
+   */
+  protected $this->langcode;
+
+  /**
    * Modules to enable.
    *
    * @var array
@@ -37,28 +44,28 @@ protected function setUp() {
     $this->config('locale.settings')
       ->set('translation.import_enabled', TRUE)
       ->save();
-  }
 
-  /**
-   * Tests basic configuration translation.
-   */
-  public function testConfigTranslation() {
     // Add custom language.
-    $langcode = 'xx';
+    $this->langcode = 'xx';
     $admin_user = $this->drupalCreateUser(array('administer languages', 'access administration pages', 'translate interface', 'administer modules', 'access site-wide contact form', 'administer contact forms'));
     $this->drupalLogin($admin_user);
     $name = $this->randomMachineName(16);
     $edit = array(
       'predefined_langcode' => 'custom',
-      'langcode' => $langcode,
+      'langcode' => $this->langcode,
       'label' => $name,
       'direction' => LanguageInterface::DIRECTION_LTR,
     );
     $this->drupalPostForm('admin/config/regional/language/add', $edit, t('Add custom language'));
     // Set path prefix.
-    $edit = array("prefix[$langcode]" => $langcode);
+    $edit = array("prefix[{$this->langcode}]" => $this->langcode);
     $this->drupalPostForm('admin/config/regional/language/detection/url', $edit, t('Save configuration'));
+  }
 
+  /**
+   * Tests basic configuration translation.
+   */
+  public function testConfigTranslation() {
     // Check site name string exists and create translation for it.
     $string = $this->storage->findString(array('source' => 'Drupal', 'context' => '', 'type' => 'configuration'));
     $this->assertTrue($string, 'Configuration strings have been created upon installation.');
@@ -67,7 +74,7 @@ public function testConfigTranslation() {
     $site_name = $this->randomMachineName(20);
     $search = array(
       'string' => $string->source,
-      'langcode' => $langcode,
+      'langcode' => $this->langcode,
       'translation' => 'all',
     );
     $this->drupalPostForm('admin/config/regional/translate', $search, t('Filter'));
@@ -80,12 +87,12 @@ public function testConfigTranslation() {
     $this->drupalPostForm('admin/config/regional/translate', $edit, t('Save translations'));
 
     // Get translation and check we've only got the site name.
-    $translation = \Drupal::languageManager()->getLanguageConfigOverride($langcode, 'system.site')->get();
+    $translation = \Drupal::languageManager()->getLanguageConfigOverride($this->langcode, 'system.site')->get();
     $this->assertEqual(count($translation), 1, 'Got the right number of properties after translation.');
     $this->assertEqual($translation['name'], $site_name, 'Got the right translation for the site name.');
 
     // Check the translated site name is displayed.
-    $this->drupalGet($langcode);
+    $this->drupalGet($this->langcode);
     $this->assertText($site_name, 'The translated site name is displayed after translations refreshed.');
 
     // Check default medium date format exists and create a translation for it.
@@ -95,7 +102,7 @@ public function testConfigTranslation() {
     // Translate using the UI so configuration is refreshed.
     $search = array(
       'string' => $string->source,
-      'langcode' => $langcode,
+      'langcode' => $this->langcode,
       'translation' => 'all',
     );
     $this->drupalPostForm('admin/config/regional/translate', $search, t('Filter'));
@@ -107,12 +114,12 @@ public function testConfigTranslation() {
     );
     $this->drupalPostForm('admin/config/regional/translate', $edit, t('Save translations'));
 
-    $translation = \Drupal::languageManager()->getLanguageConfigOverride($langcode, 'core.date_format.medium')->get();
+    $translation = \Drupal::languageManager()->getLanguageConfigOverride($this->langcode, 'core.date_format.medium')->get();
     $this->assertEqual($translation['pattern'], 'D', 'Got the right date format pattern after translation.');
 
     // Formatting the date 8 / 27 / 1985 @ 13:37 EST with pattern D should
     // display "Tue".
-    $formatted_date = format_date(494015820, $type = 'medium', NULL, NULL, $langcode);
+    $formatted_date = format_date(494015820, $type = 'medium', NULL, NULL, $this->langcode);
     $this->assertEqual($formatted_date, 'Tue', 'Got the right formatted date using the date format translation pattern.');
 
     // Assert strings from image module config are not available.
@@ -129,7 +136,7 @@ public function testConfigTranslation() {
     $this->assertTrue(isset($locations['configuration']) && isset($locations['configuration']['image.style.medium']), 'Configuration string has been created with the right location');
 
     // Check the string is unique and has no translation yet.
-    $translations = $this->storage->getTranslations(array('language' => $langcode, 'type' => 'configuration', 'name' => 'image.style.medium'));
+    $translations = $this->storage->getTranslations(array('language' => $this->langcode, 'type' => 'configuration', 'name' => 'image.style.medium'));
     $this->assertEqual(count($translations), 1);
     $translation = reset($translations);
     $this->assertEqual($translation->source, $string->source);
@@ -139,7 +146,7 @@ public function testConfigTranslation() {
     $image_style_label = $this->randomMachineName(20);
     $search = array(
       'string' => $string->source,
-      'langcode' => $langcode,
+      'langcode' => $this->langcode,
       'translation' => 'all',
     );
     $this->drupalPostForm('admin/config/regional/translate', $search, t('Filter'));
@@ -151,12 +158,12 @@ public function testConfigTranslation() {
     $this->drupalPostForm('admin/config/regional/translate', $edit, t('Save translations'));
 
     // Check the right single translation has been created.
-    $translations = $this->storage->getTranslations(array('language' => $langcode, 'type' => 'configuration', 'name' => 'image.style.medium'));
+    $translations = $this->storage->getTranslations(array('language' => $this->langcode, 'type' => 'configuration', 'name' => 'image.style.medium'));
     $translation = reset($translations);
     $this->assertTrue(count($translations) == 1 && $translation->source == $string->source && $translation->translation == $image_style_label, 'Got only one translation for image configuration.');
 
     // Try more complex configuration data.
-    $translation = \Drupal::languageManager()->getLanguageConfigOverride($langcode, 'image.style.medium')->get();
+    $translation = \Drupal::languageManager()->getLanguageConfigOverride($this->langcode, 'image.style.medium')->get();
     $this->assertEqual($translation['label'], $image_style_label, 'Got the right translation for image style name after translation');
 
     // Uninstall the module.
@@ -171,7 +178,7 @@ public function testConfigTranslation() {
     $category_label = $this->randomMachineName(20);
     $search = array(
       'string' => 'Website feedback',
-      'langcode' => $langcode,
+      'langcode' => $this->langcode,
       'translation' => 'all',
     );
     $this->drupalPostForm('admin/config/regional/translate', $search, t('Filter'));
@@ -185,7 +192,7 @@ public function testConfigTranslation() {
     // Check if this category displayed in this language will use the
     // translation. This test ensures the entity loaded from the request
     // upcasting will already work.
-    $this->drupalGet($langcode . '/contact/feedback');
+    $this->drupalGet($this->langcode . '/contact/feedback');
     $this->assertText($category_label);
 
     // Check if the UI does not show the translated String.
@@ -193,4 +200,49 @@ public function testConfigTranslation() {
     $this->assertFieldById('edit-label', 'Website feedback', 'Translation is not loaded for Edit Form.');
   }
 
+  /**
+   * Test translatability of optional configuration in locale.
+   */
+  public function testOptionalConfiguration() {
+    $this->checkNodeStrings(FALSE, FALSE);
+    // Enable the node module.
+    $this->drupalPostForm('admin/modules', array('modules[Core][node][enable]' => "1"), t('Save configuration'));
+    $this->rebuildContainer();
+    $this->checkNodeStrings(TRUE, FALSE);
+    // Enable the views module (which node provides some optional config for).
+    $this->drupalPostForm('admin/modules', array('modules[Core][views][enable]' => "1"), t('Save configuration'));
+    $this->rebuildContainer();
+    $this->checkNodeStrings(TRUE, TRUE);
+  }
+
+  /**
+   * Check that node configuration source strings are made available in locale.
+   *
+   * @param bool $required
+   *   Whether to assume a sample of the required default configuration is
+   *   present.
+   * @param bool $optional
+   *   Whether to assume a sample of the optional default configuration is
+   *   present.
+   */
+  protected function checkNodeStrings($required, $optional) {
+    // Check the required default configuration string in node.
+    $string = $this->storage->findString(array('source' => 'Make content sticky', 'context' => '', 'type' => 'configuration'));
+    if ($required) {
+      $this->assertTrue($string, 'Node action can be found with node module.');
+    }
+    else {
+      $this->assertFalse($string, 'Node action can not be found without node module.');
+    }
+
+    // Check the optional default configuration string in node.
+    $string = $this->storage->findString(array('source' => 'No front page content has been created yet.', 'context' => '', 'type' => 'configuration'));
+    if ($optional) {
+      $this->assertTrue($string, 'Node view can be found with node and views modules.');
+    }
+    else {
+      $this->assertFalse($string, 'Node view can not be found without node and/or views modules.');
+    }
+  }
+
 }