diff --git a/requirements_dev.txt b/requirements_dev.txt
index 9dbecde..c44f991 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -3,10 +3,10 @@ bumpversion==0.5.3
 wheel==0.31.1
 watchdog==0.9.0
 flake8==3.5.0
-tox==3.2.1
+tox==3.4.0
 coverage==4.5.1
-Sphinx==1.8.0
+Sphinx==1.8.1
 cryptography==2.3.1
 PyYAML==3.13
-twine==1.11.0
+twine==1.12.0