diff --git a/doc-src/Gemfile b/doc-src/Gemfile
index bdcf01b0..41535951 100644
--- a/doc-src/Gemfile
+++ b/doc-src/Gemfile
@@ -1,5 +1,9 @@
-gem 'fssm'
+disable_system_gems
+
 gem 'nanoc3', :require_as => false
 gem 'rdiscount'
-gem 'serve'
 gem 'thor'
+gem 'rack'
+gem 'mime-types'
+gem 'fssm'
+gem 'serve'
diff --git a/doc-src/README.markdown b/doc-src/README.markdown
index c4c63b99..5e0d493b 100644
--- a/doc-src/README.markdown
+++ b/doc-src/README.markdown
@@ -46,6 +46,7 @@ Your new app executables for this app are located in the bin/ directory.
 To compile (and auto recompile) and preview the site in your browser:
 
     $ cd doc-src
+    $ export RUBYLIB="../lib:../../haml/lib"
     $ bin/nanoc3 aco
 
 Then open `http://localhost:3000/` in your web browser.