diff --git a/requirements.txt b/requirements.txt
index afe16ad8..cef0adca 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,6 @@
 pbr>=0.5.21,<1.0
 argparse
 httplib2
-iso8601>=0.1.4,!=0.1.5,!=0.1.6,!=0.1.7
+iso8601>=0.1.8
 PrettyTable>=0.6,<0.8
 python-keystoneclient>=0.4.1