diff --git a/.travis.yml b/.travis.yml
index 2e3837aaf..e7261f19e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,6 +4,9 @@ python:
   - "3.3"
   - "3.4"
   - "3.5"
+cache:
+  directories:
+    $HOME/.cache/pip
 # install libjpeg-dev for Pillow to handle JPEGs
 sudo: false
 addons:
diff --git a/tox.ini b/tox.ini
index 84420bc88..ff52e29f0 100644
--- a/tox.ini
+++ b/tox.ini
@@ -8,6 +8,7 @@ envlist = py27, py35
 
 [testenv]
 commands = py.test --cov=dosage --cov=dosagelib --tb=short -n10
+passenv = TRAVIS
 # Also install optional dependencies for tests.
 deps =
     pytest-xdist