diff --git a/requirements_dev.txt b/requirements_dev.txt
index 5c9dcb6..9db5ee8 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -1,11 +1,11 @@
-pip==8.1.2
+pip==9.0.1
 bumpversion==0.5.3
-wheel==0.29.0
+wheel==0.30.0
 watchdog==0.8.3
-flake8==2.6.0
-tox==2.3.1
-coverage==4.1
-Sphinx==1.4.8
-cryptography==1.7
-PyYAML==3.11
+flake8==3.5.0
+tox==2.9.1
+coverage==4.4.2
+Sphinx==1.6.5
+cryptography==2.1.3
+PyYAML==3.12