diff --git a/LCS/PyCommon/flask_utils.py b/LCS/PyCommon/flask_utils.py
index aac22138dd61de78acc0a679c960f08cf3148298..c254c6a794361a026a10936831b54554db6af626 100644
--- a/LCS/PyCommon/flask_utils.py
+++ b/LCS/PyCommon/flask_utils.py
@@ -20,7 +20,7 @@
 # $Id$
 
 from flask import after_this_request, request
-from io import StringIO as IO
+from io import BytesIO as IO
 import gzip
 import functools
 from datetime import datetime