diff --git a/.travis.yml b/.travis.yml
index 1c6c6480..3292931a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -14,5 +14,6 @@ install:
 script:
   - set -eo pipefail
   - flake8 server/app/
+  - npm run build
   - npm run --prefix client/ test
   - pytest -s server/test
diff --git a/bin/build-client b/bin/build-client
index a4b2c484..33a900b9 100755
--- a/bin/build-client
+++ b/bin/build-client
@@ -6,6 +6,7 @@ cd $CELLXGENE_DIR
 
 npm install --prefix client/ client
 npm run  --prefix client build
+rm -rf server/app/web/static
 mkdir -p server/app/web/static/img
 cp client/build/index.html server/app/web/templates/
 cp -r client/build/static server/app/web/