diff --git a/core/core.api.php b/core/core.api.php
index 5045fc5..1281885 100644
--- a/core/core.api.php
+++ b/core/core.api.php
@@ -2468,7 +2468,8 @@ function hook_validation_constraint_alter(array &$definitions) {
  *   then be submitted via Ajax to the path specified in the #action.  Like the
  *   ajax-submit class on links, this path will have '/nojs/' replaced with
  *   '/ajax/' so that the submit handler can tell if the form was submitted in a
- *   degraded state or not.
+ *   degraded state or not. You will also need to include 'core/jquery.form' and
+ *   'core/drupal.ajax' to the form.
  * - Add property '#autocomplete_route_name' to a text field in a form. The
  *   route controller for this route must return an array of options for
  *   autocomplete, as a \Symfony\Component\HttpFoundation\JsonResponse object.