diff --git a/lower-constraints.txt b/lower-constraints.txt
index aa1d8ac52d..4b24158ffe 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -14,7 +14,7 @@ cmd2==0.8.1
 colorama==0.3.9
 contextlib2==0.5.5;python_version=='2.7'
 coverage==4.0
-cryptography==2.1.4
+cryptography==2.7
 cursive==0.2.1
 ddt==1.0.1
 debtcollector==1.19.0
diff --git a/requirements.txt b/requirements.txt
index 891bf8d62a..d516768218 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -10,7 +10,7 @@ Jinja2>=2.10 # BSD License (3 clause)
 keystonemiddleware>=4.20.0 # Apache-2.0
 lxml!=3.7.0,>=3.4.1 # BSD
 Routes>=2.3.1 # MIT
-cryptography>=2.1.4 # BSD/Apache-2.0
+cryptography>=2.7 # BSD/Apache-2.0
 WebOb>=1.8.2 # MIT
 # NOTE(mriedem): greenlet 0.4.14 does not work with older versions of gcc on
 # ppc64le systems, see https://github.com/python-greenlet/greenlet/issues/136.