diff --git a/.travis.yml b/.travis.yml
index 8518313c..e2d5bc54 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,18 +1,10 @@
-language: python
+language: minimal
 
 services:
   - docker
 
-python:
-  - "3.6"
-
-cache: pip
-
-install:
-  - pip install -r requirements.txt
-
 script:
-  - tools/ci.sh
+  - docker build .
 
 deploy:
   - provider: script
diff --git a/Dockerfile b/Dockerfile
index 046a684e..35fef53f 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -17,11 +17,15 @@ RUN pip install -r /requirements.txt \
 COPY app/server/static /doccano/app/server/static/
 COPY app/server/webpack.config.js /doccano/app/server/
 RUN cd /doccano/app/server \
- && DEBUG=False npm run build \
- && rm -rf node_modules/
+ && DEBUG=False npm run build
 
 COPY . /doccano
 
+RUN cd /doccano \
+ && tools/ci.sh
+
+RUN rm -rf /doccano/app/server/node_modules/
+
 FROM python:${PYTHON_VERSION}-slim AS runtime
 
 COPY --from=builder /deps /deps
diff --git a/tools/ci.sh b/tools/ci.sh
index 8342620e..3e4f9592 100755
--- a/tools/ci.sh
+++ b/tools/ci.sh
@@ -6,3 +6,5 @@ flake8
 python app/manage.py migrate
 python app/manage.py collectstatic
 python app/manage.py test server.tests
+
+(cd app/server && npm run lint)