diff --git a/Dockerfile b/Dockerfile
index a4818e549d8..8bdcfd8b7ef 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -25,7 +25,7 @@ FROM base as build
 RUN apt-get install --no-install-recommends -y build-essential git libpq-dev pkg-config
 
 # Install application gems
-COPY Gemfile Gemfile.lock ./
+COPY .ruby-version Gemfile Gemfile.lock ./
 RUN bundle install && \
     rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git && \
     bundle exec bootsnap precompile --gemfile