diff --git a/basicswap/basicswap.py b/basicswap/basicswap.py
index aaa4c32..a6fd01b 100644
--- a/basicswap/basicswap.py
+++ b/basicswap/basicswap.py
@@ -8,6 +8,7 @@ import os
 import re
 import sys
 import zmq
+import copy
 import json
 import time
 import base64