diff --git a/core/lib/Drupal/Core/Config/TypedConfigManagerInterface.php b/core/lib/Drupal/Core/Config/TypedConfigManagerInterface.php
index a1f2c98..84d347b 100644
--- a/core/lib/Drupal/Core/Config/TypedConfigManagerInterface.php
+++ b/core/lib/Drupal/Core/Config/TypedConfigManagerInterface.php
@@ -24,7 +24,7 @@
    * @param string $name
    *   Configuration object name.
    *
-   * @return \Drupal\Core\Config\Schema\ArrayElement
+   * @return \Drupal\Core\TypedData\TraversableTypedDataInterface
    *   Typed configuration element.
    */
   public function get($name);
diff --git a/core/modules/config_translation/src/Form/ConfigTranslationFormBase.php b/core/modules/config_translation/src/Form/ConfigTranslationFormBase.php
index 9ccb2e7..98fd84e 100644
--- a/core/modules/config_translation/src/Form/ConfigTranslationFormBase.php
+++ b/core/modules/config_translation/src/Form/ConfigTranslationFormBase.php
@@ -8,7 +8,6 @@
 namespace Drupal\config_translation\Form;
 
 use Drupal\config_translation\ConfigMapperManagerInterface;
-use Drupal\Core\Config\Schema\ArrayElement;
 use Drupal\Core\Config\TypedConfigManagerInterface;
 use Drupal\Core\TypedData\TypedDataInterface;
 use Drupal\Core\Form\BaseFormIdInterface;
diff --git a/core/modules/config_translation/src/FormElement/ListElement.php b/core/modules/config_translation/src/FormElement/ListElement.php
index 7867377..3481a0f 100644
--- a/core/modules/config_translation/src/FormElement/ListElement.php
+++ b/core/modules/config_translation/src/FormElement/ListElement.php
@@ -9,10 +9,10 @@
 
 use Drupal\Core\Config\Config;
 use Drupal\Core\Language\LanguageInterface;
-use Drupal\Core\Config\Schema\ArrayElement;
 use Drupal\config_translation\Form\ConfigTranslationFormBase;
 use Drupal\Core\StringTranslation\StringTranslationTrait;
 use Drupal\Core\TypedData\DataDefinitionInterface;
+use Drupal\Core\TypedData\TraversableTypedDataInterface;
 use Drupal\Core\TypedData\TypedDataInterface;
 use Drupal\language\Config\LanguageConfigOverride;
 
@@ -26,17 +26,17 @@ class ListElement implements ElementInterface {
   /**
    * The schema element this form is for.
    *
-   * @var \Drupal\Core\Config\Schema\ArrayElement
+   * @var \Drupal\Core\TypedData\TraversableTypedDataInterface
    */
   protected $element;
 
   /**
-   * Constructs a FormElementBase.
+   * Constructs a ListElement.
    *
-   * @param \Drupal\Core\Config\Schema\ArrayElement $element
+   * @param \Drupal\Core\TypedData\TraversableTypedDataInterface $element
    *   The schema element this form element is for.
    */
-  public function __construct(ArrayElement $element) {
+  public function __construct(TraversableTypedDataInterface $element) {
     $this->element = $element;
   }
 
@@ -58,24 +58,7 @@ public function getTranslationBuild(LanguageInterface $source_language, Language
       $element_key = implode('.', array_filter(array($base_key, $key)));
       $definition = $element->getDataDefinition();
 
-      // If this element is translatable, show a translation form. This may be a
-      // simple element, as is the case for unformatted text or date formats, or
-      // an array element, as is the case for formatted text. In the latter case
-      // the form element class is responsible for handling input for all
-      // configuration values contained in the element.
-
-      // If this is a non-translatable array element, traverse the schema
-      // further.
-
       if ($form_element = ConfigTranslationFormBase::createFormElement($element)) {
-        // For accessibility we make source and translation appear next to each
-        // other in the source for each element, which is why we utilize the
-        // 'source' and 'translation' sub-keys for the form. The form values,
-        // however, should mirror the configuration structure, so that we can
-        // traverse the configuration schema and still access the right
-        // configuration values in ConfigTranslationFormBase::setConfig().
-        // Therefore we make the 'source' and 'translation' keys the top-level
-        // keys in $form_state['values'].
         $element_parents = array_merge($parents, array($key));
         $sub_build += $form_element->getTranslationBuild($source_language, $translation_language, $source_config[$key], $translation_config[$key], $element_parents, $element_key);
 
@@ -86,7 +69,7 @@ public function getTranslationBuild(LanguageInterface $source_language, Language
         // Build sub-structure and include it with a wrapper in the form
         // if there are any translatable elements there.
         $build[$key] = array();
-        if ($element instanceof ArrayElement) {
+        if ($element instanceof TraversableTypedDataInterface) {
           $build[$key] = array(
             '#type' => 'details',
             '#title' => $this->getGroupTitle($definition, $sub_build),
diff --git a/core/modules/locale/src/LocaleConfigSubscriber.php b/core/modules/locale/src/LocaleConfigSubscriber.php
index fdf4bff..b34d556 100644
--- a/core/modules/locale/src/LocaleConfigSubscriber.php
+++ b/core/modules/locale/src/LocaleConfigSubscriber.php
@@ -10,7 +10,7 @@
 use Drupal\Core\Config\ConfigEvents;
 use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Config\ConfigOverrideCrudEvent;
-use Drupal\Core\Config\Schema\ArrayElement;
+use Drupal\Core\TypedData\TraversableTypedDataInterface;
 use Drupal\language\Config\LanguageConfigOverride;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 
@@ -108,7 +108,7 @@ public function onOverrideUpdate(ConfigOverrideCrudEvent $event) {
    *   The source configuration.
    * @param \Drupal\language\Config\LanguageConfigOverride $translation_config
    *   The language configuration override.
-   * @param \Drupal\Core\Config\Schema\ArrayElement $schema
+   * @param \Drupal\Core\TypedData\TraversableTypedDataInterface $schema
    *   The respective configuration schema.
    * @param string|null $base_key
    *   (optional) The base key that the schema and the configuration values
@@ -116,13 +116,13 @@ public function onOverrideUpdate(ConfigOverrideCrudEvent $event) {
    *   be populated consecutively when recursing into the configuration
    *   structure.
    */
-  protected function saveStrings(Config $source_config, LanguageConfigOverride $translation_config, ArrayElement $schema, $base_key = NULL) {
+  protected function saveStrings(Config $source_config, LanguageConfigOverride $translation_config, TraversableTypedDataInterface $schema, $base_key = NULL) {
     foreach ($schema as $key => $element) {
       $element_key = implode('.', array_filter(array($base_key, $key)));
 
       // We only care for strings here, so traverse the schema further in the
       // case of array elements.
-      if ($element instanceof ArrayElement) {
+      if ($element instanceof TraversableTypedDataInterface) {
         $this->saveStrings($source_config, $translation_config, $element, $element_key);
       }
       else {