diff --git a/CONTRIBUTING.markdown b/CONTRIBUTING.markdown
index 9a129154..a6d821d9 100644
--- a/CONTRIBUTING.markdown
+++ b/CONTRIBUTING.markdown
@@ -176,7 +176,7 @@ Every copy of the source files includes additional third-party tools needed buil
 
 Run `build-tools` from the main directory to build all associated third-party tools.
 
-Once the tools are built, run `marsh build` from the main directory to build the HTML documentation in the `public/docs` directory. You may now view and interact with the documentation by opening `public/docs/index.html` in your web browser.
+Once the tools are built, run `marsh build --markdown=tools/local/bin/markdown` from the main directory to build the HTML documentation in the `public/docs` directory. You may now view and interact with the documentation by opening `public/docs/index.html` in your web browser.
 
 Security restrictions in modern web browsers may prevent web fonts from displaying properly when viewing local files. One workaround is to serve the files instead of opening them directly. From the `public` directory, run `python -m http.server 8000 || python -m SimpleHTTPServer 8000` and then open `http://localhost:8000/docs/` in your web browser (requires Python).