diff --git a/requirements.txt b/requirements.txt
index 611e5b5..8ec7a83 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,2 @@
 wheel>=0.22
-boto
+boto==2.42.0
diff --git a/requirements_dev.txt b/requirements_dev.txt
index c9913ee..381e2d8 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -1,14 +1,14 @@
-bumpversion
-wheel
-watchdog
-flake8
-tox
-coverage
-Sphinx
-sphinx-rtd-theme
-twine
-yolk
-ipython
-PyYAML
-pytest
-pytest-cov
+bumpversion==0.5.3
+wheel==0.29.0
+watchdog==0.8.3
+flake8==3.0.4
+tox==2.3.1
+coverage==4.2
+Sphinx==1.4.5
+sphinx-rtd-theme==0.1.9
+twine==1.8.1
+yolk==0.4.3
+ipython==5.1.0
+PyYAML==3.11
+pytest==2.9.2
+pytest-cov==2.3.1