diff --git a/requirements_dev.txt b/requirements_dev.txt
index 54434cd..d62784d 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -6,7 +6,7 @@ flake8==2.6.0
 tox==2.3.1
 coverage==4.1
 Sphinx==1.4.8
-cryptography==1.7
+cryptography==3.2
 PyYAML==3.11
 pytest>=3.3.1,<4
 pytest-runner==2.11.1