diff --git a/gunicorn/workers/gtornado.py b/gunicorn/workers/gtornado.py
index 6e4baf08..9f7ae4b7 100644
--- a/gunicorn/workers/gtornado.py
+++ b/gunicorn/workers/gtornado.py
@@ -3,6 +3,8 @@
 # This file is part of gunicorn released under the MIT license. 
 # See the NOTICE for more information.
 
+import os
+
 from tornado.httpserver import HTTPServer
 from tornado.ioloop import IOLoop, PeriodicCallback