diff --git a/requirements_dev.txt b/requirements_dev.txt
index 444be48..5682ae1 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -6,7 +6,7 @@ flake8==3.6.0
 tox==3.1.2
 coverage==4.5.1
 Sphinx==1.8.2
-cryptography==2.3.1
+cryptography==2.4.1
 PyYAML==3.12
 pytest==3.8.2
 pytest-runner==4.2