diff --git a/requirements-bench.txt b/requirements-bench.txt
index 2676540..13019ba 100644
--- a/requirements-bench.txt
+++ b/requirements-bench.txt
@@ -1,4 +1,4 @@
-matplotlib
+matplotlib==1.5.3
 scipy>=0.13.3
 numpy>=1.8.1
 -r requirements.txt
diff --git a/requirements.txt b/requirements.txt
index e918cb8..1d91207 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,12 +5,12 @@ pyzmq>=14.2.0
 wheel>=0.23.0
 coverage>=3.7
 docutils>=0.11
-elpy
-jedi
-rope_py3k
-ipython
-ipdb
-sphinx
-sphinxcontrib-spelling
-readthedocs-sphinx-ext
+elpy==1.12.0
+jedi==0.9.0
+rope-py3k==0.9.4-1
+ipython==5.1.0
+ipdb==0.10.1
+sphinx==1.4.6
+sphinxcontrib-spelling==2.2.0
+readthedocs-sphinx-ext==0.5.4
 -e .