diff --git a/includes/webform.form_alter.inc b/includes/webform.form_alter.inc
index 6ce8b8cb8..139439a59 100644
--- a/includes/webform.form_alter.inc
+++ b/includes/webform.form_alter.inc
@@ -32,7 +32,7 @@ function webform_form_alter(&$form, FormStateInterface $form_state, $form_id) {
   }
 
   // Display editing original language warning.
-  if (\Drupal::moduleHandler()->moduleExists('config_translation') && preg_match('/^entity.webform.(?:edit|settings|assets|access|handlers|third_party_settings)_form$/', \Drupal::routeMatch()->getRouteName())) {
+  if (\Drupal::moduleHandler()->moduleExists('config_translation') && preg_match('/^entity.webform.(?:edit|settings|assets|access|handlers|third_party_settings)_form$/', \Drupal::routeMatch()->getRouteName() ?? "")) {
     /** @var \Drupal\webform\WebformInterface $webform */
     $webform = \Drupal::routeMatch()->getParameter('webform');
     /** @var \Drupal\Core\Language\LanguageManagerInterface $language_manager */