diff --git a/.travis.yml b/.travis.yml
index 6044dc8..c948528 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,3 +8,4 @@ branches:
 script:
   - npm install -g @mapbox/mapbox-gl-style-spec
   - gl-style-validate style.json
+  - diff <(gl-style-format style.json) style.json