diff --git a/core/lib/Drupal/Core/Template/Attribute.php b/core/lib/Drupal/Core/Template/Attribute.php
index b2196245fa1748b797c2be461c48905f50927ff8..076cfd3485c2025cf1620b336a2c64a149453347 100644
--- a/core/lib/Drupal/Core/Template/Attribute.php
+++ b/core/lib/Drupal/Core/Template/Attribute.php
@@ -7,8 +7,6 @@
 
 namespace Drupal\Core\Template;
 
-use ArrayAccess;
-use IteratorAggregate;
 
 /**
  * A class that can be used for collecting then rendering HTML attributtes.
@@ -32,7 +30,7 @@
  *  // Produces <cat class="cat black-cat white-cat black-white-cat" id="socks">
  * @endcode
  */
-class Attribute implements ArrayAccess, IteratorAggregate {
+class Attribute implements \ArrayAccess, \IteratorAggregate {
 
   /**
    * Stores the attribute data.
@@ -129,7 +127,7 @@ public function  __clone() {
    * Implements IteratorAggregate::getIterator().
    */
   public function getIterator() {
-    return new ArrayIterator($this->storage);
+    return new \ArrayIterator($this->storage);
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Template/AttributeArray.php b/core/lib/Drupal/Core/Template/AttributeArray.php
index d4f87713c48dbcb9815c73c5c2699e8ed9e4bc2b..d3521e03b4e6d3d0db9ae2954582cbd0d6bc8029 100644
--- a/core/lib/Drupal/Core/Template/AttributeArray.php
+++ b/core/lib/Drupal/Core/Template/AttributeArray.php
@@ -7,8 +7,6 @@
 
 namespace Drupal\Core\Template;
 
-use ArrayAccess;
-use IteratorAggregate;
 
 /**
  * A class that defines a type of Attribute that can be added to as an array.
@@ -28,7 +26,7 @@
  *
  * @see Drupal\Core\Template\Attribute
  */
-class AttributeArray extends AttributeValueBase implements ArrayAccess, IteratorAggregate {
+class AttributeArray extends AttributeValueBase implements \ArrayAccess, \IteratorAggregate {
 
   /**
    * Implements ArrayAccess::offsetGet().
@@ -75,7 +73,7 @@ public function __toString() {
    * Implements IteratorAggregate::getIterator().
    */
   public function getIterator() {
-    return new ArrayIterator($this->value);
+    return new \ArrayIterator($this->value);
   }
 
   /**
diff --git a/core/modules/system/lib/Drupal/system/Tests/Common/AttributesUnitTest.php b/core/modules/system/lib/Drupal/system/Tests/Common/AttributesUnitTest.php
index 894e0abf32c58b648f487999c0a60c7da8567e67..6910f7ad61f6fe3653e85207ca271625ffed3390 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Common/AttributesUnitTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Common/AttributesUnitTest.php
@@ -47,5 +47,11 @@ function testDrupalAttributes() {
 
     // Verify empty attributes array is rendered.
     $this->assertIdentical((string) new Attribute(array()), '', 'Empty attributes array.');
+
+    $attributes_array = array('key1' => 'value1');
+    $attribute = new Attribute($attributes_array);
+    foreach($attribute as $value) {
+      $this->assertIdentical((string) $value, 'value1', 'Iterate over attribute.');
+    }
   }
 }