diff --git a/README.textile b/README.textile
index af90a9f3..8f4dfec1 100644
--- a/README.textile
+++ b/README.textile
@@ -34,6 +34,7 @@ and run the software from there.
 
   $ sudo gem install RedCloth
   $ sudo gem install liquid
+  $ sudo gem install classifier
   
   $ git clone git://github.com/mojombo/jekyll
   $ cd jekyll