diff --git a/core/includes/form.inc b/core/includes/form.inc
index c1617a2..ee836a5 100644
--- a/core/includes/form.inc
+++ b/core/includes/form.inc
@@ -31,6 +31,18 @@ function drupal_form_submit($form_arg, FormStateInterface $form_state) {
 }
 
 /**
+ * Processes a form submission.
+ *
+ * @deprecated in Drupal 8.x-dev, will be removed before Drupal 8.0.
+ *   Use \Drupal::formBuilder()->processForm().
+ *
+ * @see \Drupal\Core\Form\FormBuilderInterface::processForm().
+ */
+function drupal_process_form($form_id, &$form, FormStateInterface $form_state) {
+  \Drupal::formBuilder()->processForm($form_id, $form, $form_state);
+}
+
+/**
  * Executes custom validation and submission handlers for a given form.
  *
  * @deprecated in Drupal 8.x-dev, will be removed before Drupal 8.0.