diff --git a/requirements-dev.txt b/requirements-dev.txt
index 3687298..8504656 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -1,8 +1,8 @@
 -e .
-ipython
-ipdb
-pytest
-pytest-cov
-flake8
-tox
-pygments
+ipython==5.1.0
+ipdb==0.10.1
+pytest==3.0.2
+pytest-cov==2.3.1
+flake8==3.0.4
+tox==2.3.1
+pygments==2.1.3