diff --git a/Dockerfile b/Dockerfile
index 0a429c4..34491b7 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,9 +4,13 @@
 #   docker run --rm=true "catphish:${TAG}" --Domain ring0labs.com --All
 FROM ruby:2.3.4-alpine
 
+RUN apk --no-cache add g++ make
+RUN gem install unf_ext --no-ri --no-rdoc
+
 # Install it into the /opt/ dir
 WORKDIR /opt/catphish
-ADD * /opt/catphish/
+ADD Gemfile \
+    catphish.rb /opt/catphish/
 RUN bundle install
 
 # Use the script as the entrypoint so we can supply args directly to the docker daemon
diff --git a/README.md b/README.md
index c618637..e3f322f 100644
--- a/README.md
+++ b/README.md
@@ -96,7 +96,7 @@ $ docker run \
     --rm=true \
     "catphish:${TAG}" \
         --Domain ring0labs.com \
-        --All
+        generate --All
 ```
 
 # In Action