diff --git a/requirements_dev.txt b/requirements_dev.txt
index 4b4c668..6c702a9 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -6,7 +6,7 @@ flake8==3.7.9
 tox==3.14.0
 coverage==4.5.4
 Sphinx==2.2.1
-cryptography==2.7
+cryptography==2.8
 PyYAML==5.1.2
 pytest==5.2.2
 pytest-runner==5.1