diff --git a/misuzu.php b/misuzu.php
index d9b61438..287dcdf3 100644
--- a/misuzu.php
+++ b/misuzu.php
@@ -2,3 +2,5 @@
 namespace Misuzu;
 
 require_once 'vendor/autoload.php';
+
+Application::start()->debug(IO\Directory::exists(__DIR__ . '/vendor/phpunit/phpunit'));
diff --git a/tests/FileSystemTest.php b/tests/FileSystemTest.php
index e4d3b177..96c3cd5a 100644
--- a/tests/FileSystemTest.php
+++ b/tests/FileSystemTest.php
@@ -42,7 +42,7 @@ class FileSystemTest extends TestCase
 
     public function testWriteFile()
     {
-        $file = new FileStream(WORKING_DIR . '/file', FileStream::MODE_TRUNCATE, false);
+        $file = new FileStream(WORKING_DIR . '/file', FileStream::MODE_TRUNCATE);
         $this->assertInstanceOf(FileStream::class, $file);
 
         $file->write('misuzu');