diff --git a/README.md b/README.md
index c9517de..3f237dd 100644
--- a/README.md
+++ b/README.md
@@ -31,7 +31,7 @@ We take the privacy of your data very seriously. Here are some of the technical
 
 ### Testing
 
-You can download a prebuilt bundle under [releases](https://github.com/whiteout-io/mail-html5/releases) or build your own from source (requires [node.js and npm](http://nodejs.org/download/)):
+You can download a prebuilt bundle under [releases](https://github.com/whiteout-io/mail-html5/releases) or build your own from source (requires [node.js](http://nodejs.org/download/), [grunt](http://gruntjs.com/getting-started#installing-the-cli) and [sass](http://sass-lang.com/install)):
 
     npm install && npm test