diff --git a/requirements_dev.txt b/requirements_dev.txt
index 8d9ab21..f75babd 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -6,7 +6,7 @@ flake8==3.6.0
 tox==3.5.3
 coverage==4.5.1
 Sphinx==1.8.3
-cryptography==2.4.1
+cryptography==2.6.1
 PyYAML==3.12
 pytest==4.0.2
 pytest-runner==4.4