diff --git a/phpstan-bootstrap.php b/phpstan-bootstrap.php
index adc6cfa187..99acf96227 100644
--- a/phpstan-bootstrap.php
+++ b/phpstan-bootstrap.php
@@ -1,6 +1,6 @@
 <?php
 
-require_once 'system/Test/bootstrap.php';
+require __DIR__ . '/system/Test/bootstrap.php';
 
 if (! defined('OCI_COMMIT_ON_SUCCESS')) {
     define('OCI_COMMIT_ON_SUCCESS', 32);