diff --git a/warcprox/controller.py b/warcprox/controller.py
index 9a2880e..84c3b93 100644
--- a/warcprox/controller.py
+++ b/warcprox/controller.py
@@ -37,6 +37,7 @@ import doublethink
 import importlib
 import queue
 import socket
+import os
 
 class Factory:
     @staticmethod