diff --git a/lib/generators/dockerfile_generator.rb b/lib/generators/dockerfile_generator.rb
index 4b8cbaf..9423bb2 100644
--- a/lib/generators/dockerfile_generator.rb
+++ b/lib/generators/dockerfile_generator.rb
@@ -1169,7 +1169,7 @@ def procfile
         nginx: '/usr/sbin/nginx -g "daemon off;"',
         rails: "./bin/rails server -p 3001"
       }
-    elsif options.thruster? || @gemfile.include?("thruster")
+    elsif using_thruster?
       {
         rails: "bundle exec thrust ./bin/rails server"
       }
@@ -1180,6 +1180,10 @@ def procfile
     end
   end
 
+  def using_thruster?
+    options.thruster? || @gemfile.include?("thruster")
+  end
+
   def fly_processes
     return unless File.exist? "fly.toml"
     return unless using_sidekiq? || using_solidq?
diff --git a/lib/generators/templates/Dockerfile.erb b/lib/generators/templates/Dockerfile.erb
index 6ea9475..e3cea42 100644
--- a/lib/generators/templates/Dockerfile.erb
+++ b/lib/generators/templates/Dockerfile.erb
@@ -296,7 +296,7 @@ EOF
 
 <% end -%>
 # Start the server by default, this can be overwritten at runtime
-EXPOSE 3000
+EXPOSE <%= using_thruster? ? '80' : '3000' %>
 <% if deploy_database == 'sqlite3' -%>
 VOLUME /data
 <% end -%>
diff --git a/test/results/thruster/Dockerfile b/test/results/thruster/Dockerfile
new file mode 100644
index 0000000..18f25b6
--- /dev/null
+++ b/test/results/thruster/Dockerfile
@@ -0,0 +1,72 @@
+# syntax = docker/dockerfile:1
+
+# Make sure RUBY_VERSION matches the Ruby version in .ruby-version and Gemfile
+ARG RUBY_VERSION=xxx
+FROM ruby:$RUBY_VERSION-slim as base
+
+# Rails app lives here
+WORKDIR /rails
+
+# Set production environment
+ENV BUNDLE_DEPLOYMENT="1" \
+    BUNDLE_PATH="/usr/local/bundle" \
+    BUNDLE_WITHOUT="development:test" \
+    RAILS_ENV="production"
+
+# Update gems and bundler
+RUN gem update --system --no-document && \
+    gem install -N bundler
+
+
+# Throw-away build stage to reduce size of final image
+FROM base as build
+
+# Install packages needed to build gems
+RUN apt-get update -qq && \
+    apt-get install --no-install-recommends -y build-essential pkg-config
+
+# Install application gems
+COPY --link Gemfile Gemfile.lock ./
+RUN bundle install && \
+    bundle exec bootsnap precompile --gemfile && \
+    rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git
+
+# Copy application code
+COPY --link . .
+
+# Precompile bootsnap code for faster boot times
+RUN bundle exec bootsnap precompile app/ lib/
+
+# Precompiling assets for production without requiring secret RAILS_MASTER_KEY
+RUN SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile
+
+
+# Final stage for app image
+FROM base
+
+# Install packages needed for deployment
+RUN apt-get update -qq && \
+    apt-get install --no-install-recommends -y curl libsqlite3-0 && \
+    rm -rf /var/lib/apt/lists /var/cache/apt/archives
+
+# Copy built artifacts: gems, application
+COPY --from=build "${BUNDLE_PATH}" "${BUNDLE_PATH}"
+COPY --from=build /rails /rails
+
+# Run and own only the runtime files as a non-root user for security
+RUN groupadd --system --gid 1000 rails && \
+    useradd rails --uid 1000 --gid 1000 --create-home --shell /bin/bash && \
+    mkdir /data && \
+    chown -R 1000:1000 db log storage tmp /data
+USER 1000:1000
+
+# Deployment options
+ENV DATABASE_URL="sqlite3:///data/production.sqlite3"
+
+# Entrypoint prepares the database.
+ENTRYPOINT ["/rails/bin/docker-entrypoint"]
+
+# Start the server by default, this can be overwritten at runtime
+EXPOSE 80
+VOLUME /data
+CMD ["bundle", "exec", "thrust", "./bin/rails", "server"]
diff --git a/test/test_thruster.rb b/test/test_thruster.rb
new file mode 100644
index 0000000..a9a0226
--- /dev/null
+++ b/test/test_thruster.rb
@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+require_relative "base"
+
+class TestThruster < TestBase
+  @generate_options = "--thruster"
+
+  def test_thruster
+    check_dockerfile
+  end
+end