diff --git a/core/lib/Drupal/Core/Config/Schema/ArrayElement.php b/core/lib/Drupal/Core/Config/Schema/ArrayElement.php
index f801c28724bb94378a46955a8a5e307094df7874..8becdd7f0fff7b409806324b000cdafd870be741 100644
--- a/core/lib/Drupal/Core/Config/Schema/ArrayElement.php
+++ b/core/lib/Drupal/Core/Config/Schema/ArrayElement.php
@@ -6,17 +6,12 @@
  */
 
 namespace Drupal\Core\Config\Schema;
-
-use \ArrayAccess;
-use \ArrayIterator;
-use \Countable;
-use \IteratorAggregate;
-use \Traversable;
+use Drupal\Core\TypedData\TraversableTypedDataInterface;
 
 /**
  * Defines a generic configuration element that contains multiple properties.
  */
-abstract class ArrayElement extends Element implements IteratorAggregate, ArrayAccess, Countable {
+abstract class ArrayElement extends Element implements \IteratorAggregate, TraversableTypedDataInterface, \ArrayAccess, \Countable {
 
   /**
    * Parsed elements.
@@ -26,8 +21,8 @@ abstract class ArrayElement extends Element implements IteratorAggregate, ArrayA
   /**
    * Gets an array of contained elements.
    *
-   * @return array
-   *   Array of \Drupal\Core\Config\Schema\ArrayElement objects.
+   * @return \Drupal\Core\TypedData\TypedDataInterface[]
+   *   An array of elements contained in this element.
    */
   protected function getElements() {
     if (!isset($this->elements)) {
@@ -49,8 +44,8 @@ protected function getAllKeys() {
   /**
    * Builds an array of contained elements.
    *
-   * @return array
-   *   Array of \Drupal\Core\Config\Schema\ArrayElement objects.
+   * @return \Drupal\Core\TypedData\TypedDataInterface[]
+   *   An array of elements contained in this element.
    */
   protected abstract function parse();
 
@@ -111,7 +106,7 @@ public function count() {
    * Implements IteratorAggregate::getIterator();
    */
   public function getIterator() {
-    return new ArrayIterator($this->getElements());
+    return new \ArrayIterator($this->getElements());
   }
 
 }
diff --git a/core/lib/Drupal/Core/Config/Schema/SchemaCheckTrait.php b/core/lib/Drupal/Core/Config/Schema/SchemaCheckTrait.php
index 4d2bd11658ad8c25bc5a455131859baec99afdc7..0fccd471564f419430f530ad2a35ed2b91ed0bd6 100644
--- a/core/lib/Drupal/Core/Config/Schema/SchemaCheckTrait.php
+++ b/core/lib/Drupal/Core/Config/Schema/SchemaCheckTrait.php
@@ -9,6 +9,7 @@
 
 use Drupal\Core\Config\TypedConfigManagerInterface;
 use Drupal\Core\TypedData\PrimitiveInterface;
+use Drupal\Core\TypedData\TraversableTypedDataInterface;
 use Drupal\Core\TypedData\Type\BooleanInterface;
 use Drupal\Core\TypedData\Type\StringInterface;
 use Drupal\Core\TypedData\Type\FloatInterface;
@@ -108,7 +109,7 @@ protected function checkValue($key, $value) {
     }
     else {
       $errors = array();
-      if (!$element instanceof ArrayElement) {
+      if (!$element instanceof TraversableTypedDataInterface) {
         $errors[$error_key] = 'Non-scalar value but not defined as an array (such as mapping or sequence).';
       }
 
diff --git a/core/lib/Drupal/Core/Config/Schema/Sequence.php b/core/lib/Drupal/Core/Config/Schema/Sequence.php
index e5b6a356ed33ae06d6e93e1bfc9adb932b79530f..630bb50d1b9beef1b239eed681f76243c73afbf5 100644
--- a/core/lib/Drupal/Core/Config/Schema/Sequence.php
+++ b/core/lib/Drupal/Core/Config/Schema/Sequence.php
@@ -22,7 +22,7 @@ class Sequence extends ArrayElement implements ListInterface {
   protected $itemDefinition;
 
   /**
-   * Overrides ArrayElement::parse()
+   * {@inheritdoc}
    */
   protected function parse() {
     // Creates a new data definition object for each item from the generic type
diff --git a/core/lib/Drupal/Core/TypedData/ComplexDataInterface.php b/core/lib/Drupal/Core/TypedData/ComplexDataInterface.php
index 1397485f92cacfc9fb2dfdf7f44c85cdd8dd7a24..0a5b38a5ceb64037a1aa651e95c8927b2dc24314 100644
--- a/core/lib/Drupal/Core/TypedData/ComplexDataInterface.php
+++ b/core/lib/Drupal/Core/TypedData/ComplexDataInterface.php
@@ -23,7 +23,7 @@
  *
  * @ingroup typed_data
  */
-interface ComplexDataInterface extends \Traversable, TypedDataInterface  {
+interface ComplexDataInterface extends TraversableTypedDataInterface  {
 
   /**
    * Gets a property object.
diff --git a/core/lib/Drupal/Core/TypedData/ListInterface.php b/core/lib/Drupal/Core/TypedData/ListInterface.php
index ce59dfb35afb5cc3bdc19f88220e9a3f6bdea3fe..2c5dbc7f6f05cfced59ef36f6fb58b03c830e175 100644
--- a/core/lib/Drupal/Core/TypedData/ListInterface.php
+++ b/core/lib/Drupal/Core/TypedData/ListInterface.php
@@ -20,7 +20,7 @@
  *
  * @ingroup typed_data
  */
-interface ListInterface extends TypedDataInterface, \ArrayAccess, \Countable, \Traversable {
+interface ListInterface extends TraversableTypedDataInterface, \ArrayAccess, \Countable {
 
   /**
    * Determines whether the list contains any non-empty items.
diff --git a/core/lib/Drupal/Core/TypedData/TraversableTypedDataInterface.php b/core/lib/Drupal/Core/TypedData/TraversableTypedDataInterface.php
new file mode 100644
index 0000000000000000000000000000000000000000..d42557ee752d78e97f0351bf10564accd81c6a27
--- /dev/null
+++ b/core/lib/Drupal/Core/TypedData/TraversableTypedDataInterface.php
@@ -0,0 +1,13 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\TypedData\TraversableTypedDataInterface.
+ */
+
+namespace Drupal\Core\TypedData;
+
+/**
+ * An interface for typed data objects that can be traversed.
+ */
+interface TraversableTypedDataInterface extends TypedDataInterface, \Traversable {}
diff --git a/core/lib/Drupal/Core/TypedData/TypedData.php b/core/lib/Drupal/Core/TypedData/TypedData.php
index b0f614c4b075d3b094e041cf704e94f7038f95e4..3216d21668883699da45f674022819ebdae5f4d2 100644
--- a/core/lib/Drupal/Core/TypedData/TypedData.php
+++ b/core/lib/Drupal/Core/TypedData/TypedData.php
@@ -39,14 +39,14 @@ abstract class TypedData implements TypedDataInterface, PluginInspectionInterfac
   /**
    * The parent typed data object.
    *
-   * @var \Drupal\Core\TypedData\TypedDataInterface
+   * @var \Drupal\Core\TypedData\TraversableTypedDataInterface|null
    */
   protected $parent;
 
   /**
    * {@inheritdoc}
    */
-  public static function createInstance($definition, $name = NULL, TypedDataInterface $parent = NULL) {
+  public static function createInstance($definition, $name = NULL, TraversableTypedDataInterface $parent = NULL) {
     return new static($definition, $name, $parent);
   }
 
@@ -153,7 +153,7 @@ public function applyDefaultValue($notify = TRUE) {
   /**
    * {@inheritdoc}
    */
-  public function setContext($name = NULL, TypedDataInterface $parent = NULL) {
+  public function setContext($name = NULL, TraversableTypedDataInterface $parent = NULL) {
     $this->parent = $parent;
     $this->name = $name;
   }
diff --git a/core/lib/Drupal/Core/TypedData/TypedDataInterface.php b/core/lib/Drupal/Core/TypedData/TypedDataInterface.php
index 74d083fe567e2b01d046d03d9b223766404fd223..7b038e51c19d71eca8efcd6d41c56edcb7b26faa 100644
--- a/core/lib/Drupal/Core/TypedData/TypedDataInterface.php
+++ b/core/lib/Drupal/Core/TypedData/TypedDataInterface.php
@@ -26,7 +26,7 @@ interface TypedDataInterface {
    * @param string|null $name
    *   (optional) The name of the created property, or NULL if it is the root
    *   of a typed data tree. Defaults to NULL.
-   * @param \Drupal\Core\TypedData\TypedDataInterface $parent
+   * @param \Drupal\Core\TypedData\TraversableTypedDataInterface $parent
    *   (optional) The parent object of the data property, or NULL if it is the
    *   root of a typed data tree. Defaults to NULL.
    *
@@ -36,7 +36,7 @@ interface TypedDataInterface {
    *
    * @see \Drupal\Core\TypedData\TypedDataManager::create()
    */
-  public static function createInstance($definition, $name = NULL, TypedDataInterface $parent = NULL);
+  public static function createInstance($definition, $name = NULL, TraversableTypedDataInterface $parent = NULL);
 
   /**
    * Gets the data definition.
@@ -122,7 +122,7 @@ public function getName();
   /**
    * Returns the parent data structure; i.e. either complex data or a list.
    *
-   * @return \Drupal\Core\TypedData\ComplexDataInterface|\Drupal\Core\TypedData\ListInterface
+   * @return \Drupal\Core\TypedData\TraversableTypedDataInterface|null
    *   The parent data structure, either complex data or a list; or NULL if this
    *   is the root of the typed data tree.
    */
@@ -134,7 +134,7 @@ public function getParent();
    * Returns the root data for a tree of typed data objects; e.g. for an entity
    * field item the root of the tree is its parent entity object.
    *
-   * @return \Drupal\Core\TypedData\ComplexDataInterface|\Drupal\Core\TypedData\ListInterface
+   * @return \Drupal\Core\TypedData\TraversableTypedDataInterface
    *   The root data structure, either complex data or a list.
    */
   public function getRoot();
@@ -159,9 +159,9 @@ public function getPropertyPath();
    * @param string|null $name
    *   (optional) The name of the property or the delta of the list item,
    *   or NULL if it is the root of a typed data tree. Defaults to NULL.
-   * @param \Drupal\Core\TypedData\TypedDataInterface|null $parent
+   * @param \Drupal\Core\TypedData\TraversableTypedDataInterface|null $parent
    *   (optional) The parent object of the data property, or NULL if it is the
    *   root of a typed data tree. Defaults to NULL.
    */
-  public function setContext($name = NULL, TypedDataInterface $parent = NULL);
+  public function setContext($name = NULL, TraversableTypedDataInterface $parent = NULL);
 }
diff --git a/core/modules/config_translation/src/ConfigMapperManager.php b/core/modules/config_translation/src/ConfigMapperManager.php
index 9a0b46e413daf12d86d9b68cfdc9b95ffc096ecf..09b64986ec3c84154dcdaf1cb525ceb46a189545 100644
--- a/core/modules/config_translation/src/ConfigMapperManager.php
+++ b/core/modules/config_translation/src/ConfigMapperManager.php
@@ -10,7 +10,6 @@
 use Drupal\Component\Utility\String;
 use Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException;
 use Drupal\Core\Cache\CacheBackendInterface;
-use Drupal\Core\Config\Schema\ArrayElement;
 use Drupal\Core\Config\TypedConfigManagerInterface;
 use Drupal\Core\Extension\ModuleHandlerInterface;
 use Drupal\Core\Extension\ThemeHandlerInterface;
@@ -20,6 +19,7 @@
 use Drupal\Core\Plugin\Discovery\YamlDiscovery;
 use Drupal\Core\Plugin\Discovery\ContainerDerivativeDiscoveryDecorator;
 use Drupal\Core\Plugin\Factory\ContainerFactory;
+use Drupal\Core\TypedData\TraversableTypedDataInterface;
 use Drupal\Core\TypedData\TypedDataInterface;
 use Symfony\Component\Routing\RouteCollection;
 
@@ -176,7 +176,7 @@ public function hasTranslatable($name) {
   protected function findTranslatable(TypedDataInterface $element) {
     // In case this is a sequence or a mapping check whether any child element
     // is translatable.
-    if ($element instanceof ArrayElement) {
+    if ($element instanceof TraversableTypedDataInterface) {
       foreach ($element as $child_element) {
         if ($this->findTranslatable($child_element)) {
           return TRUE;
diff --git a/core/modules/config_translation/tests/src/Unit/ConfigMapperManagerTest.php b/core/modules/config_translation/tests/src/Unit/ConfigMapperManagerTest.php
index c28b663a4b8997c82a947c8e90bdcc9449b7398c..cdf89b5a50f2a137d74fb4508af63c68531eeebd 100644
--- a/core/modules/config_translation/tests/src/Unit/ConfigMapperManagerTest.php
+++ b/core/modules/config_translation/tests/src/Unit/ConfigMapperManagerTest.php
@@ -170,9 +170,12 @@ protected function getElement(array $definition) {
    *   A nested schema element, containing the passed-in elements.
    */
   protected function getNestedElement(array $elements) {
-    // ConfigMapperManager::findTranslatable() checks for the abstract class
-    // \Drupal\Core\Config\Schema\ArrayElement, but mocking that directly does
-    // not work.
+    // ConfigMapperManager::findTranslatable() checks for
+    // \Drupal\Core\TypedData\TraversableTypedDataInterface, but mocking that
+    // directly does not work, because we need to implement \IteratorAggregate
+    // in order for getIterator() to be called. Therefore we need to mock
+    // \Drupal\Core\Config\Schema\ArrayElement, but that is abstract, so we
+    // need to mock one of the subclasses of it.
     $nested_element = $this->getMockBuilder('Drupal\Core\Config\Schema\Mapping')
       ->disableOriginalConstructor()
       ->getMock();
diff --git a/core/modules/locale/src/LocaleTypedConfig.php b/core/modules/locale/src/LocaleTypedConfig.php
index ab373fe85f9a4216d476ba0e06dfaad717656172..ee0b470e81d9dbccf6eef6894a28360635341192 100644
--- a/core/modules/locale/src/LocaleTypedConfig.php
+++ b/core/modules/locale/src/LocaleTypedConfig.php
@@ -10,8 +10,9 @@
 use Drupal\Core\TypedData\ContextAwareInterface;
 use Drupal\Core\TypedData\DataDefinitionInterface;
 use Drupal\Core\Config\Schema\Element;
-use Drupal\Core\Config\Schema\ArrayElement;
 use Drupal\Core\Config\TypedConfigManagerInterface;
+use Drupal\Core\TypedData\TraversableTypedDataInterface;
+use Drupal\Core\TypedData\TypedDataInterface;
 
 /**
  * Defines the locale configuration wrapper object.
@@ -114,9 +115,8 @@ protected function canTranslate($from_langcode, $to_langcode) {
   /**
    * Gets translated configuration data for a typed configuration element.
    *
-   * @param mixed $element
-   *   Typed configuration element, either \Drupal\Core\Config\Schema\Element or
-   *   \Drupal\Core\Config\Schema\ArrayElement.
+   * @param \Drupal\Core\TypedData\TypedDataInterface $element
+   *   Typed configuration element.
    * @param array $options
    *   Array with translation options that must contain the keys defined in
    *   \Drupal\locale\LocaleTypedConfig::translateElement().
@@ -125,9 +125,9 @@ protected function canTranslate($from_langcode, $to_langcode) {
    *   Configuration data translated to the requested language if available,
    *   an empty array otherwise.
    */
-  protected function getElementTranslation($element, array $options) {
+  protected function getElementTranslation(TypedDataInterface $element, array $options) {
     $translation = array();
-    if ($element instanceof ArrayElement) {
+    if ($element instanceof TraversableTypedDataInterface) {
       $translation = $this->getArrayTranslation($element, $options);
     }
     elseif ($this->translateElement($element, $options)) {
@@ -137,9 +137,9 @@ protected function getElementTranslation($element, array $options) {
   }
 
   /**
-   * Gets translated configuration data for an element of type ArrayElement.
+   * Gets translated configuration data for a traversable element.
    *
-   * @param \Drupal\Core\Config\Schema\ArrayElement $element
+   * @param \Drupal\Core\TypedData\TraversableTypedDataInterface $element
    *   Typed configuration array element.
    * @param array $options
    *   Array with translation options that must contain the keys defined in
@@ -148,7 +148,7 @@ protected function getElementTranslation($element, array $options) {
    * @return array
    *   Configuration data translated to the requested language.
    */
-  protected function getArrayTranslation(ArrayElement $element, array $options) {
+  protected function getArrayTranslation(TraversableTypedDataInterface $element, array $options) {
     $translation = array();
     foreach ($element as $key => $property) {
       $value = $this->getElementTranslation($property, $options);
@@ -179,7 +179,7 @@ protected function getArrayTranslation(ArrayElement $element, array $options) {
    * @return bool
    *   Whether the element fits the translation criteria.
    */
-  protected function translateElement(\Drupal\Core\TypedData\TypedDataInterface $element, array $options) {
+  protected function translateElement(TypedDataInterface $element, array $options) {
     if ($this->canTranslate($options['source'], $options['target'])) {
       $definition = $element->getDataDefinition();
       $value = $element->getValue();
diff --git a/core/tests/Drupal/Tests/Core/Entity/TypedData/EntityAdapterUnitTest.php b/core/tests/Drupal/Tests/Core/Entity/TypedData/EntityAdapterUnitTest.php
index 5556c6edd0d7b0ae04b6a68a86514d5239900e02..0628c89945a32758b38101d03a6f933e101bedf7 100644
--- a/core/tests/Drupal/Tests/Core/Entity/TypedData/EntityAdapterUnitTest.php
+++ b/core/tests/Drupal/Tests/Core/Entity/TypedData/EntityAdapterUnitTest.php
@@ -252,7 +252,7 @@ public function testGetParent() {
    */
   public function testSetContext() {
     $name = $this->randomMachineName();
-    $parent = $this->getMock('\Drupal\Core\TypedData\TypedDataInterface');
+    $parent = $this->getMock('\Drupal\Core\TypedData\TraversableTypedDataInterface');
     // Our mocked entity->setContext() returns NULL, so assert that.
     $this->assertNull($this->entityAdapter->setContext($name, $parent));
     $this->assertEquals($name, $this->entityAdapter->getName());