diff --git a/.travis.yml b/.travis.yml
index 695bae2d..02e3fd7b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,6 +8,7 @@ before_install:
   - sudo apt-get update
   - sudo apt-get -y install ruby openjdk-8-jre
   - sudo gem install asciidoctor asciidoctor-diagram
+  - sudo apt-get -y install graphviz
 script:
   - npm install -g codecov
   - npm test && codecov