.../src/Plugin/Field/FieldFormatter/CommentDefaultFormatter.php       | 4 ++--
 .../field/src/Tests/EntityReference/EntityReferenceFormatterTest.php  | 1 +
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/core/modules/comment/src/Plugin/Field/FieldFormatter/CommentDefaultFormatter.php b/core/modules/comment/src/Plugin/Field/FieldFormatter/CommentDefaultFormatter.php
index 251dce0..be747b4 100644
--- a/core/modules/comment/src/Plugin/Field/FieldFormatter/CommentDefaultFormatter.php
+++ b/core/modules/comment/src/Plugin/Field/FieldFormatter/CommentDefaultFormatter.php
@@ -157,7 +157,7 @@ public function viewElements(FieldItemListInterface $items) {
       // Unpublished comments are not included in
       // $entity->get($field_name)->comment_count, but unpublished comments
       // should display if the user is an administrator.
-      $output['comments']['#cache']['contexts'][] = 'user.roles';
+      $elements['#cache']['contexts'][] = 'user.roles';
       if ($this->currentUser->hasPermission('access comments') || $this->currentUser->hasPermission('administer comments')) {
         // This is a listing of Comment entities, so associate its list cache
         // tag for correct invalidation.
@@ -183,7 +183,7 @@ public function viewElements(FieldItemListInterface $items) {
       // display below the entity. Do not show the form for the print view mode.
       if ($status == CommentItemInterface::OPEN && $comment_settings['form_location'] == CommentItemInterface::FORM_BELOW && $this->viewMode != 'print') {
         // Only show the add comment form if the user has permission.
-        $output['comments']['#cache']['contexts'][] = 'user.roles';
+        $elements['#cache']['contexts'][] = 'user.roles';
         if ($this->currentUser->hasPermission('post comments')) {
           // All users in the "anonymous" role can use the same form: it is fine
           // for this form to be stored in the render cache.
diff --git a/core/modules/field/src/Tests/EntityReference/EntityReferenceFormatterTest.php b/core/modules/field/src/Tests/EntityReference/EntityReferenceFormatterTest.php
index d940188..9120f4a 100644
--- a/core/modules/field/src/Tests/EntityReference/EntityReferenceFormatterTest.php
+++ b/core/modules/field/src/Tests/EntityReference/EntityReferenceFormatterTest.php
@@ -230,6 +230,7 @@ public function testLabelFormatter() {
     $expected_item_2 = array(
       '#markup' => $this->unsavedReferencedEntity->label(),
       '#cache' => array(
+        'contexts' => [],
         'tags' => $this->unsavedReferencedEntity->getCacheTags(),
       ),
     );