diff --git a/tests/Bootstrap.php b/tests/Bootstrap.php
index 13d691007..b8f588d18 100644
--- a/tests/Bootstrap.php
+++ b/tests/Bootstrap.php
@@ -1,8 +1,8 @@
 <?php declare(strict_types=1);
 
 \ini_set('memory_limit', '2048M');
-\ini_set('display_errors', 1);
-\ini_set('display_startup_errors', 1);
+\ini_set('display_errors', '1');
+\ini_set('display_startup_errors', '1');
 \error_reporting(\E_ALL);
 
 if (\file_exists('vendor/autoload.php')) {