diff --git a/.travis.yml b/.travis.yml
index 3ffbc3c..c54d3b1 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,6 +6,7 @@ addons:
 before_script:
   - npm install -g polymer-cli
   - polymer install --variants
+  - git checkout package-lock.json
   - >-
     npm run update-types && git diff --exit-code || (echo -e
     '\n\033[31mERROR:\033[0m Typings are stale. Please run "npm run