diff -u b/core/modules/comment/lib/Drupal/comment/Plugin/Field/FieldFormatter/CommentDefaultFormatter.php b/core/modules/comment/lib/Drupal/comment/Plugin/Field/FieldFormatter/CommentDefaultFormatter.php
--- b/core/modules/comment/lib/Drupal/comment/Plugin/Field/FieldFormatter/CommentDefaultFormatter.php
+++ b/core/modules/comment/lib/Drupal/comment/Plugin/Field/FieldFormatter/CommentDefaultFormatter.php
@@ -145,20 +145,6 @@
           if ($this->getSetting('pager_id')) {
             $build['pager']['#element'] = $this->getSetting('pager_id');
           }
-          // The viewElements() method of entity field formatters is run
-          // during the #pre_render phase of rendering an entity. A formatter
-          // builds the content of the field in preparation for theming.
-          // All entity cache tags must be available after the #pre_render phase.
-          // This field formatter is highly exceptional: it renders *another*
-          // entity and this referenced entity has its own #pre_render
-          // callbacks. In order collect the cache tags associated with the
-          // referenced entity it must be passed to drupal_render() so that its
-          // #pre_render callbacks are invoked and its full build array is
-          // assembled. Rendering the referenced entity in place here will allow
-          // its cache tags to be bubbled up and included with those of the
-          // main entity when cache tags are collected for a renderable array
-          // in drupal_render().
-          drupal_render($build, TRUE);
           $output['comments'] = $build;
         }
       }
diff -u b/core/modules/entity_reference/lib/Drupal/entity_reference/Plugin/Field/FieldFormatter/EntityReferenceEntityFormatter.php b/core/modules/entity_reference/lib/Drupal/entity_reference/Plugin/Field/FieldFormatter/EntityReferenceEntityFormatter.php
--- b/core/modules/entity_reference/lib/Drupal/entity_reference/Plugin/Field/FieldFormatter/EntityReferenceEntityFormatter.php
+++ b/core/modules/entity_reference/lib/Drupal/entity_reference/Plugin/Field/FieldFormatter/EntityReferenceEntityFormatter.php
@@ -93,22 +93,7 @@
       }
 
       if (!empty($item->target_id)) {
-        // The viewElements() method of entity field formatters is run
-        // during the #pre_render phase of rendering an entity. A formatter
-        // builds the content of the field in preparation for theming.
-        // All entity cache tags must be available after the #pre_render phase.
-        // This field formatter is highly exceptional: it renders *another*
-        // entity and this referenced entity has its own #pre_render
-        // callbacks. In order collect the cache tags associated with the
-        // referenced entity it must be passed to drupal_render() so that its
-        // #pre_render callbacks are invoked and its full build array is
-        // assembled. Rendering the referenced entity in place here will allow
-        // its cache tags to be bubbled up and included with those of the
-        // main entity when cache tags are collected for a renderable array
-        // in drupal_render().
-        $referenced_entity_build = entity_view($item->entity, $view_mode, $item->getLangcode());
-        drupal_render($referenced_entity_build, TRUE);
-        $elements[$delta] = $referenced_entity_build;
+        $elements[$delta] = entity_view($item->entity, $view_mode, $item->getLangcode());
 
         if (empty($links) && isset($result[$delta][$target_type][$item->target_id]['links'])) {
           // Hide the element links.