diff --git a/gns3server/modules/docker/__init__.py b/gns3server/modules/docker/__init__.py
index f0aaa2e9..f0f19669 100644
--- a/gns3server/modules/docker/__init__.py
+++ b/gns3server/modules/docker/__init__.py
@@ -24,6 +24,7 @@ import logging
 import aiohttp
 import urllib
 import json
+import sys
 from gns3server.utils import parse_version
 
 log = logging.getLogger(__name__)