diff --git a/README.md b/README.md
index 5f561116a..0ae48f640 100644
--- a/README.md
+++ b/README.md
@@ -14,6 +14,7 @@ What you'll need to use it:
 - [nanoc](nanoc.stoneship.org) → `gem install nanoc`
 - [zsh](zsh.org) → Installed by default on most good system
 - A bunch of gems: `gem install kramdown builder sass rainpress`
+- Optionally if you want to serve locally: `gem install unicorn rack rack-contrib rack-rewrite mime-types`
 
 Optionally