diff --git a/requirements_dev.txt b/requirements_dev.txt
index bffeb36..a936a84 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -7,7 +7,7 @@ flake8==3.5.0
 tox==2.9.1
 coverage==4.4.1
 Sphinx==1.6.7
-cryptography==2.7
+cryptography==3.2
 PyYAML==3.12
 pytest==3.4.0
 pytest-runner==3.0