diff --git a/requirements_dev.txt b/requirements_dev.txt
index 395cd99..ff18dba 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -6,7 +6,7 @@ flake8==3.3.0
 tox==2.6.0
 coverage==4.3.4
 Sphinx==1.5.3
-cryptography==1.7.2
+cryptography==1.9
 PyYAML==3.12
 pytest==3.0.6
 mock==2.0.0
\ No newline at end of file