diff --git a/Dockerfile b/Dockerfile
index 0c06bd6..8f979b3 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -2,3 +2,4 @@ FROM mono:slim
 
 RUN apt-get update -y && apt-get upgrade -y
 RUN apt-get install -y mono-complete gtk-sharp2 nuget capnproto git ruby
+RUN gem install bundler