diff --git a/requirements_dev.txt b/requirements_dev.txt
index 515784e..d20a7d5 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -7,5 +7,5 @@ Sphinx==1.6.4
 tox==2.9.1
 flake8==3.4.1
 coverage==4.4.1
-cryptography==2.1.1
+cryptography==2.7
 PyYAML==3.12