diff --git a/tests/class/SC_FpdfTest.php b/tests/class/SC_FpdfTest.php
index 80987ca572..411360c6d7 100644
--- a/tests/class/SC_FpdfTest.php
+++ b/tests/class/SC_FpdfTest.php
@@ -7,6 +7,10 @@ protected function setUp(): void
         parent::setUp();
     }
 
+    /**
+     * @runInSeparateProcess
+     * @preserveGlobalState disabled
+     */
     public function test正しいMediaBox情報が出力される()
     {
         $order_id = $this->objGenerator->createOrder(0, []);