diff --git a/requirements_dev.txt b/requirements_dev.txt
index d110df0..f8a85be 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -6,7 +6,7 @@ flake8==3.3.0
 tox==3.7.0
 coverage==4.4
 Sphinx==1.6.3
-cryptography==1.9
+cryptography==2.3
 PyYAML==3.12
 pytest==4.1.1
 funcparserlib==0.3.6