diff --git a/core/includes/utility.inc b/core/includes/utility.inc
index 3d9ec1c..5b2719d 100644
--- a/core/includes/utility.inc
+++ b/core/includes/utility.inc
@@ -17,6 +17,8 @@
  *
  * @return string
  *   The variable exported in a way compatible to Drupal's coding standards.
+ *
+ * @deprecated Use \Drupal\Component\Utility\Variable::export().
  */
 function drupal_var_export($var, $prefix = '') {
   return Variable::export($var, $prefix);