diff --git a/core/includes/batch.inc b/core/includes/batch.inc
index 5bac4fe..8a8f7f2 100644
--- a/core/includes/batch.inc
+++ b/core/includes/batch.inc
@@ -389,7 +389,7 @@ function _batch_next_set() {
       // We use our stored copies of $form and $form_state to account for
       // possible alterations by previous form submit handlers.
       $complete_form = &$batch['form_state']->getCompleteForm();
-      call_user_func_array($callback, array($complete_form, &$batch['form_state']));
+      call_user_func_array($callback, array(&$complete_form, &$batch['form_state']));
     }
     return TRUE;
   }
diff --git a/core/lib/Drupal/Core/Form/FormBuilder.php b/core/lib/Drupal/Core/Form/FormBuilder.php
index 5c9a927..ab1c1c5 100644
--- a/core/lib/Drupal/Core/Form/FormBuilder.php
+++ b/core/lib/Drupal/Core/Form/FormBuilder.php
@@ -753,7 +753,7 @@ public function doBuildForm($form_id, &$element, FormStateInterface &$form_state
     if (isset($element['#process']) && !$element['#processed']) {
       foreach ($element['#process'] as $process) {
         $complete_form = &$form_state->getCompleteForm();
-        $element = call_user_func_array($process, array(&$element, &$form_state, $complete_form));
+        $element = call_user_func_array($process, array(&$element, &$form_state, &$complete_form));
       }
       $element['#processed'] = TRUE;
     }
diff --git a/core/lib/Drupal/Core/Form/FormValidator.php b/core/lib/Drupal/Core/Form/FormValidator.php
index 4e964d1..830ed56 100644
--- a/core/lib/Drupal/Core/Form/FormValidator.php
+++ b/core/lib/Drupal/Core/Form/FormValidator.php
@@ -252,7 +252,7 @@ protected function doValidateForm(&$elements, FormStateInterface &$form_state, $
       elseif (isset($elements['#element_validate'])) {
         foreach ($elements['#element_validate'] as $callback) {
           $complete_form = &$form_state->getCompleteForm();
-          call_user_func_array($callback, array(&$elements, &$form_state, $complete_form));
+          call_user_func_array($callback, array(&$elements, &$form_state, &$complete_form));
         }
       }