diff --git a/tox.ini b/tox.ini
index 6ff9c95e01..0772c245d2 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,8 +4,8 @@ envlist = py26, py27, pypy
 [testenv]
 deps =
     nose
-    mock
-    coverage>=4.0a5
+    mock==1.0.1
+    coverage==4.0a5
     unittest2
     git+https://github.com/Metaswitch/python-etcd.git@3f14a002c9a75df3242de3d81a91a2e6bd32c5a8#egg=python-etcd
 commands=nosetests --with-coverage
@@ -16,8 +16,8 @@ commands=nosetests --with-coverage
 commands=nosetests calico/felix/test calico/test
 deps =
     nose
-    mock
-    coverage>=4.0a5
+    mock==1.0.1
+    coverage==4.0a5
     unittest2
     git+https://github.com/Metaswitch/python-etcd.git@3f14a002c9a75df3242de3d81a91a2e6bd32c5a8#egg=python-etcd
-    git+https://github.com/surfly/gevent.git#egg=gevent
+    gevent>=1.1a2