diff --git a/requirements.txt b/requirements.txt
index 34f87ece36..08798d786b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,7 +5,7 @@
 pbr>=1.8 # Apache-2.0
 Babel>=2.3.4 # BSD
 croniter>=0.3.4 # MIT License
-cryptography!=1.3.0,>=1.0 # BSD/Apache-2.0
+cryptography>=1.6 # BSD/Apache-2.0
 debtcollector>=1.2.0 # Apache-2.0
 eventlet!=0.18.3,>=0.18.2 # MIT
 keystoneauth1>=2.18.0 # Apache-2.0