diff --git a/requirements_dev.txt b/requirements_dev.txt
index a3796ee..1caa8a5 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -7,7 +7,7 @@ tox==3.5.3
 coverage==4.5.2
 pytest-aiohttp==0.3.0
 Sphinx==1.8.2
-cryptography==2.4.1
+cryptography==2.7
 PyYAML==4.2b4
 pytest==4.0.0
 docutils==0.14