diff --git a/Dockerfile b/Dockerfile
index 2058ff6a1651c91e348766369c49433959e14267..038474171398d2078cc83198afae09ed4bf8b005 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -80,6 +80,7 @@ RUN curl http://apt.postgresql.org/pub/repos/apt/ACCC4CF8.asc | apt-key add - \
  && cd /home/discourse/discourse \
  && git remote set-branches --add origin tests-passed \
  && sed -i 's/daemonize true/daemonize false/g' ./config/puma.rb \
+ && sed -i "s/msgpack (1.4.1)/msgpack (1.4.2)/" Gemfile.lock \
  && bundle config build.nokogiri --use-system-libraries \
  && bundle install --deployment --verbose --without test --without development --retry 3 --jobs 4 \
  && find /home/discourse/discourse/vendor/bundle -name tmp -type d -exec rm -rf {} + \