diff --git a/requirements_dev.txt b/requirements_dev.txt
index ea58bfb..5fea1ed 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -1,13 +1,13 @@
-bump2version
+bump2version==0.5.10
 coverage==4.5.2
-flake8==3.6.0
+flake8==3.7.7
 mock==2.0.0
-pip==18.1
-pytest==4.0.2
-pytest-runner==4.2
+pip==19.0.3
+pytest==4.3.0
+pytest-runner==4.4
 six==1.12.0
-Sphinx==1.8.3
-tox==3.6.1
-twine==1.12.1
+Sphinx==1.8.4
+tox==3.7.0
+twine==1.13.0
 watchdog==0.9.0
-wheel==0.32.3
+wheel==0.33.1