diff --git a/requirements_dev.txt b/requirements_dev.txt
index 8a58527..5bc9e39 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -6,7 +6,7 @@ flake8==3.2.1
 tox==2.5.0
 coverage==4.2
 Sphinx==1.5.1
-cryptography==1.7.1
+cryptography==39.0.1
 PyYAML==3.12
 pytest==3.0.5
 twine==1.8.1