diff --git a/requirements_dev.txt b/requirements_dev.txt
index 014b44a..c67ed28 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -1,12 +1,12 @@
-pip==8.1.2
+pip==9.0.1
 bumpversion==0.5.3
 wheel==0.29.0
 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
-pytest==2.9.2
+flake8==3.4.1
+tox==2.7.0
+coverage==4.4.1
+Sphinx==1.6.3
+cryptography==2.0.3
+PyYAML==3.12
+pytest==3.2.1
 pytest-runner==2.11.1