diff --git a/.travis.yml b/.travis.yml
index a49992a9b..f68e784af 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -20,7 +20,7 @@ matrix:
 install:
     - travis_retry sudo apt-get update
     - travis_retry sudo apt-get install -qq bash-completion mp3gain
-    - travis_retry pip install tox
+    - travis_retry pip install tox sphinx
     - "[ ! -z $COVERAGE ] && travis_retry pip install coveralls || true"
 
 script: tox -e $TOX_ENV