diff --git c/core/modules/locale/lib/Drupal/locale/Form/ExportForm.php w/core/modules/locale/lib/Drupal/locale/Form/ExportForm.php
index 2c4b3bc..1f59bc4 100644
--- c/core/modules/locale/lib/Drupal/locale/Form/ExportForm.php
+++ w/core/modules/locale/lib/Drupal/locale/Form/ExportForm.php
@@ -102,7 +102,8 @@ public function buildForm(array $form, array &$form_state) {
   /**
    * {@inheritdoc}
    */
-  public function submitForm(array &$form, array &$form_state, Request $request) {
+  public function submitForm(array &$form, array &$form_state) {
+    $request = $this->getRequest();
     // If template is required, language code is not given.
     if ($form_state['values']['langcode'] != Language::LANGCODE_SYSTEM) {
       $language = language_load($form_state['values']['langcode']);