diff --git a/.travis.yml b/.travis.yml
index 8ccab17361..67834c2f72 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -25,6 +25,7 @@ install:
 before_script:
     - export DISPLAY=:99.0
     - sh -e /etc/init.d/xvfb start
+    - npm i
     - node_modules/.bin/gulp build
 script:
     - test/runtests.sh -x firefox/firefox