diff --git a/core/modules/datetime/lib/Drupal/datetime/Plugin/Field/FieldFormatter/DateTimeDefaultFormatter.php b/core/modules/datetime/lib/Drupal/datetime/Plugin/Field/FieldFormatter/DateTimeDefaultFormatter.php
index e03395a..754ffc0 100644
--- a/core/modules/datetime/lib/Drupal/datetime/Plugin/Field/FieldFormatter/DateTimeDefaultFormatter.php
+++ b/core/modules/datetime/lib/Drupal/datetime/Plugin/Field/FieldFormatter/DateTimeDefaultFormatter.php
@@ -116,14 +116,12 @@ public function viewElements(FieldItemListInterface $items) {
       }
 
       // Display the date using theme datetime.
-      // @todo How should RDFa attributes be added to this?
       $elements[$delta] = array(
         '#theme' => 'datetime',
         '#text' => $formatted_date,
         '#html' => FALSE,
         '#attributes' => array(
           'datetime' => $iso_date,
-          'datatype' => 'xsd:dateTime',
         ),
       );
       if (!empty($item->_attributes)) {