diff --git a/setup.py b/setup.py
index 5a384fe..0c9689a 100755
--- a/setup.py
+++ b/setup.py
@@ -15,7 +15,7 @@
           'simplejson==3.11.1',
           'python-dateutil>=2.6.0',
           'backoff==1.8.0',
-	  'ciso8601',
+	  'ciso8601==2.1.1',
       ],
       extras_require={
           'dev': [