diff --git a/requirements-ci.txt b/requirements-ci.txt
index 2055adf67..386fd4340 100644
--- a/requirements-ci.txt
+++ b/requirements-ci.txt
@@ -1,12 +1,12 @@
 -r requirements-wheel.txt
-pip
-flake8
+pip==8.1.2
+flake8==3.0.4
 pyflakes>=1.0.0
-coverage
-sphinx
+coverage==4.2
+sphinx==1.4.6
 alabaster>=0.6.2
-tox
-sphinxcontrib-newsfeed
-pytest-cov
-pygments
+tox==2.3.1
+sphinxcontrib-newsfeed==0.1.4
+pytest-cov==2.3.1
+pygments==2.1.3
 -e .
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 6bf6272ef..a0b7b9299 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -1,6 +1,6 @@
 -r requirements-ci.txt
-ipdb
-pytest-sugar
-ipython
-pyenchant
-sphinxcontrib-spelling
+ipdb==0.10.1
+pytest-sugar==0.7.1
+ipython==5.1.0
+pyenchant==1.6.8
+sphinxcontrib-spelling==2.2.0
diff --git a/requirements-wheel.txt b/requirements-wheel.txt
index 01401e5f8..4c4c94774 100644
--- a/requirements-wheel.txt
+++ b/requirements-wheel.txt
@@ -1,3 +1,3 @@
-cython
-pytest
+cython==0.24.1
+pytest==3.0.2