diff --git a/core/includes/ajax.inc b/core/includes/ajax.inc
index 3a0fe4a..de6f5d0 100644
--- a/core/includes/ajax.inc
+++ b/core/includes/ajax.inc
@@ -245,7 +245,7 @@ function ajax_render($commands = array()) {
       $items[$type] = array();
     }
     else {
-      $function = 'drupal_add_' . $type;
+      $function = '_drupal_add_' . $type;
       $items[$type] = $function();
       drupal_alter($type, $items[$type]);
       // @todo Inline CSS and JS items are indexed numerically. These can't be
diff --git a/core/includes/common.inc b/core/includes/common.inc
index 5bf91ab..0099008 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -1676,8 +1676,8 @@ function drupal_get_css($css = NULL, $skip_alter = FALSE) {
  * @param $b
  *   Second item for comparison.
  *
- * @see drupal_add_css()
- * @see drupal_add_js()
+ * @see _drupal_add_css()
+ * @see _drupal_add_js()
  */
 function drupal_sort_css_js($a, $b) {
   // First order by group, so that all items in the CSS_AGGREGATE_DEFAULT group
@@ -2517,7 +2517,7 @@ function drupal_process_attached($elements, $dependency_check = FALSE) {
         $data = $options['data'];
         unset($options['data']);
       }
-      call_user_func('drupal_add_' . $type, $data, $options);
+      call_user_func('_drupal_add_' . $type, $data, $options);
     }
     unset($elements['#attached'][$type]);
   }
diff --git a/core/lib/Drupal/Core/Ajax/AjaxResponse.php b/core/lib/Drupal/Core/Ajax/AjaxResponse.php
index bdf5970..95242f3 100644
--- a/core/lib/Drupal/Core/Ajax/AjaxResponse.php
+++ b/core/lib/Drupal/Core/Ajax/AjaxResponse.php
@@ -104,7 +104,7 @@ protected function ajaxRender(Request $request) {
         $items[$type] = array();
       }
       else {
-        $function = 'drupal_add_' . $type;
+        $function = '_drupal_add_' . $type;
         $items[$type] = $function();
         drupal_alter($type, $items[$type]);
         // @todo Inline CSS and JS items are indexed numerically. These can't be