diff --git a/artiq/tools.py b/artiq/tools.py
index f8f4314bf..f7a399db7 100644
--- a/artiq/tools.py
+++ b/artiq/tools.py
@@ -3,6 +3,7 @@ import logging
 import sys
 import asyncio
 import collections
+import atexit
 import string
 import os