diff --git a/tox.ini b/tox.ini
index e1bf1f43..f61c3157 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,8 @@
 [tox]
 envlist = py25, py26, py27, py32
 [testenv]
+setenv =
+    XDG_CACHE_HOME={envtmpdir}/cache
 commands =
     python regression.py
     python run.py