diff --git a/README.md b/README.md
index c8706d9..2873701 100644
--- a/README.md
+++ b/README.md
@@ -20,6 +20,7 @@ We include a lightweight Go server in `server.go`.
 To build the site:
 
 ```console
+$ go get github.com/russross/blackfriday
 $ tools/build
 $ open public/index.html
 ```