diff --git a/Dockerfile b/Dockerfile
index 9bdb568..af19285 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,6 +4,7 @@ RUN mkdir /app
 WORKDIR /app
 ADD Gemfile /app/Gemfile
 ADD Gemfile.lock /app/Gemfile.lock
+RUN gem install bundler
 RUN bundle install --jobs=8 --without development test
 ADD . /app
 CMD ["unicorn", "-c", "./config/unicorn.rb"]