diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index 7783347..b37eeca 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -4,5 +4,6 @@ include __DIR__ . '/../vendor/autoload.php'; // composer autoload
 $kernel = \AspectMock\Kernel::getInstance();
 $kernel->init([
     'debug' => true,
+    'cacheDir' => sys_get_temp_dir(),
     'includePaths' => [__DIR__ . '/../src']
 ]);