diff --git a/src/Symfony/Component/HttpKernel/Tests/Log/LoggerTest.php b/src/Symfony/Component/HttpKernel/Tests/Log/LoggerTest.php
index 7354000b16..17865203f2 100644
--- a/src/Symfony/Component/HttpKernel/Tests/Log/LoggerTest.php
+++ b/src/Symfony/Component/HttpKernel/Tests/Log/LoggerTest.php
@@ -34,7 +34,7 @@ class LoggerTest extends TestCase
 
     protected function setUp()
     {
-        $this->tmpFile = sys_get_temp_dir().\DIRECTORY_SEPARATOR.'log';
+        $this->tmpFile = tempnam(sys_get_temp_dir(), 'log');
         $this->logger = new Logger(LogLevel::DEBUG, $this->tmpFile);
     }