diff --git a/tests/src/Functional/HandlePdfControllerTest.php b/tests/src/Functional/HandlePdfControllerTest.php
index e18c0e8d25cfc0c4e67f443489231c482cbae76d..5abd559abd848a7c8bad36f6ad5d07ef538399eb 100644
--- a/tests/src/Functional/HandlePdfControllerTest.php
+++ b/tests/src/Functional/HandlePdfControllerTest.php
@@ -18,6 +18,13 @@ use Symfony\Component\HttpFoundation\ResponseHeaderBag;
  */
 class HandlePdfControllerTest extends FillPdfUploadTestBase {
 
+  /**
+   * Array of nodes to run tests with.
+   *
+   * @var array
+   */
+  private $testNodes = [];
+
   /**
    * {@inheritdoc}
    */