diff --git a/core/modules/book/lib/Drupal/book/Tests/BookTest.php b/core/modules/book/lib/Drupal/book/Tests/BookTest.php
index f4ad875..6f18189 100644
--- a/core/modules/book/lib/Drupal/book/Tests/BookTest.php
+++ b/core/modules/book/lib/Drupal/book/Tests/BookTest.php
@@ -488,7 +488,7 @@ function testBookNodeTypeChange() {
    */
   public function testBookOrdering() {
     // Create new book.
-    $nodes = $this->createBook();
+    $this->createBook();
     $book = $this->book;
 
     $this->drupalLogin($this->admin_user);