diff --git a/dev-requirements.txt b/dev-requirements.txt
new file mode 100644
index 0000000..932a895
--- /dev/null
+++ b/dev-requirements.txt
@@ -0,0 +1 @@
+mock
diff --git a/requirements.txt b/requirements.txt
index 0a95d3d..7800f0f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1 @@
 redis
-mock
diff --git a/tox.ini b/tox.ini
index bb92511..c167801 100644
--- a/tox.ini
+++ b/tox.ini
@@ -3,9 +3,12 @@ envlist=py26,py27,py33,pypy
 
 [testenv]
 commands=py.test []
-deps=pytest
+deps=
+    pytest
+    mock
 
 [testenv:py26]
 deps=
     pytest
     unittest2
+    mock