diff --git a/monorepo/stubs/helpers.php b/monorepo/stubs/helpers.php
index 821a819bebd..5aeaaf54ed0 100644
--- a/monorepo/stubs/helpers.php
+++ b/monorepo/stubs/helpers.php
@@ -6,7 +6,7 @@
  * @param  class-string<T>  $abstract
  * @return T
  */
-function app(string $abstract)
+function app(string $abstract = null)
 {
 }