diff --git a/core/modules/book/lib/Drupal/book/Controller/BookController.php b/core/modules/book/lib/Drupal/book/Controller/BookController.php
index e94ea3f..33dcdd7 100644
--- a/core/modules/book/lib/Drupal/book/Controller/BookController.php
+++ b/core/modules/book/lib/Drupal/book/Controller/BookController.php
@@ -111,7 +111,7 @@ public function bookRender() {
    *
    * @throws \Symfony\Component\HttpKernel\Exception\NotFoundHttpException
    */
-  public function book_export($type, EntityInterface $node) {
+  public function bookExport($type, EntityInterface $node) {
     $type = drupal_strtolower($type);
 
     $export_function = 'book_export_' . $type;