diff --git a/core/modules/datetime/src/Plugin/Field/FieldWidget/DateTimeTimestampWidget.php b/core/modules/datetime/src/Plugin/Field/FieldWidget/DateTimeTimestampWidget.php
index 84b6776..f3e03fc 100644
--- a/core/modules/datetime/src/Plugin/Field/FieldWidget/DateTimeTimestampWidget.php
+++ b/core/modules/datetime/src/Plugin/Field/FieldWidget/DateTimeTimestampWidget.php
@@ -47,7 +47,8 @@ public function formElement(FieldItemListInterface $items, $delta, array $elemen
   public function massageFormValues(array $values, array $form, FormStateInterface $form_state) {
     foreach ($values as &$item) {
       $date = NULL;
-      // @todo Why is the structure different when the field is visible or not?
+      // @todo The structure is different whether access is denied or not, to
+      //   be fixed in https://www.drupal.org/node/2326533.
       if (isset($item['value']) && $item['value'] instanceof DrupalDateTime) {
         $date = $item['value'];
       }