diff --git a/Dockerfile b/Dockerfile
index e963674a5..eaa92f0c2 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -123,3 +123,4 @@ RUN cd ~ && \
 # Set the work dir and the container entry point
 WORKDIR /opt/mastodon
 ENTRYPOINT ["/tini", "--"]
+EXPOSE 3000 4000