diff --git a/decanlp/server.py b/decanlp/server.py
index 1bd28e26..140f6ed7 100644
--- a/decanlp/server.py
+++ b/decanlp/server.py
@@ -37,6 +37,7 @@ import numpy as np
 import random
 import asyncio
 import logging
+import sys
 from copy import deepcopy
 from pprint import pformat