diff --git a/requirements_dev.txt b/requirements_dev.txt
index a4a9e7a..719b19e 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -6,7 +6,7 @@ flake8==3.7.7
 tox==3.9.0
 coverage==4.5.3
 Sphinx==2.0.1
-cryptography==2.6.1
+cryptography==2.7
 PyYAML==3.12
 pytest==4.5.0
 pytest-runner==4.4