diff --git a/includes/content.node_form.inc b/includes/content.node_form.inc
index 6515fde..29d6e6d 100644
--- a/includes/content.node_form.inc
+++ b/includes/content.node_form.inc
@@ -273,6 +273,8 @@ function content_add_more_js($type_name_url, $field_name) {
     drupal_json(array('data' => ''));
     exit;
   }
+  // Poor man's submit: Just build the form, in order to execute value callbacks.
+  $form = form_builder($_POST['form_id'], $form, $form_state);
 
   // Build our new form element for the whole field,
   // and let other modules alter it.