diff --git a/Dockerfile b/Dockerfile
index f5eb088933b8c69c24b94eae2f8418b6c24cda38..c28287cca8708e3468b3fcd459935a6a8da4a7a5 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,8 +1,13 @@
 FROM ruby:2.3.1-alpine
 
+LABEL maintainer="https://github.com/tootsuite/mastodon" \
+      description="A GNU Social-compatible microblogging server"
+
 ENV RAILS_ENV=production \
     NODE_ENV=production
 
+EXPOSE 3000 4000
+
 WORKDIR /mastodon
 
 COPY Gemfile Gemfile.lock package.json yarn.lock /mastodon/