diff --git a/requirements_dev.txt b/requirements_dev.txt
index f04bbf7..3c92e12 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -6,7 +6,7 @@ flake8==3.5.0
 tox==2.9.1
 coverage==4.4.2
 Sphinx==1.6.5
-cryptography==2.1.3
+cryptography==2.3
 PyYAML==3.12
 pytest==3.2.5
 pytest-runner==3.0