diff --git a/.travis.yml b/.travis.yml
index 49fad446533e3f0dae73c6db8734c85b45d2c30a..b401b501487e27b06a06f08b8f629e4f8d037097 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -9,7 +9,8 @@ install:
   - sudo apt-get install python-pip
   - sudo /usr/bin/pip install git+git://github.com/pyinvoke/invoke.git
   - 'if [ -n "${NACL+x}" ]; then invoke install-nacl --library=$NACL; fi'
-  - invoke install --dev
+  - 'if [ -n "${NACL+x}" ]; then invoke install --dev; fi'
+  - 'if [ -n "${NACL-x}" ]; then pip install pep8 pylint; fi'
 script:
   - invoke tests --suite=$SUITE
 env: