diff --git a/setup.py b/setup.py
index dc346e1..3e71c30 100644
--- a/setup.py
+++ b/setup.py
@@ -12,7 +12,7 @@ sys.path.insert(0, os.path.join(os.path.dirname(__file__), 'src'))  # noqa
 import flake8
 
 
-tests_require = ['mock', 'pytest']
+tests_require = ['mock >= 2.0.0', 'pytest']
 
 requires = [
     "pyflakes >= 0.8.1, != 1.2.0, != 1.2.1, != 1.2.2, < 1.4.0",
diff --git a/tox.ini b/tox.ini
index 2e4504f..b72f3ad 100644
--- a/tox.ini
+++ b/tox.ini
@@ -4,7 +4,7 @@ envlist = py27,py33,py34,py35,flake8,linters,docs
 
 [testenv]
 deps =
-    mock
+    mock>=2.0.0
     pytest
     coverage
 commands =