diff --git a/requirements.txt b/requirements.txt
index 9ea2195..4530002 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,8 +1,8 @@
-coverage
-coveralls
-pyflakes
-pylint
-nose
-mock
-six
-ipython
+coverage==4.5.1
+coveralls==1.5.1
+pyflakes==2.0.0
+pylint==2.1.1
+nose==1.3.7
+mock==2.0.0
+six==1.11.0
+ipython==7.0.1