diff --git a/requirements/dev.txt b/requirements/dev.txt
index 4e3aa37..d2076bb 100644
--- a/requirements/dev.txt
+++ b/requirements/dev.txt
@@ -8,7 +8,7 @@ flake8-docstrings==1.1.0
 tox==2.7.0
 coverage==4.4.1
 Sphinx==1.6.1
-cryptography==1.8.1
+cryptography==1.9
 PyYAML==3.12
 pytest==3.1.0
 click==6.7