diff --git a/ipaacalib/python/src/ipaaca/iu.py b/ipaacalib/python/src/ipaaca/iu.py
index bb193434be72640f0e77f017cdace6a959db813a..fd55bd78a3dc7b15ae248432cbce202331d8323e 100644
--- a/ipaacalib/python/src/ipaaca/iu.py
+++ b/ipaacalib/python/src/ipaaca/iu.py
@@ -37,6 +37,7 @@ import copy
 import threading
 import uuid
 
+import ipaaca_pb2
 import ipaaca.converter
 import ipaaca.exception
 import ipaaca.misc