diff --git a/docs/_docs/index.md b/docs/_docs/index.md
index 07dfeb11..af97b79c 100644
--- a/docs/_docs/index.md
+++ b/docs/_docs/index.md
@@ -41,6 +41,9 @@ bundle exec jekyll serve
 ```
 6. Browse to [http://localhost:4000](http://localhost:4000){:target="_blank"}
 
+{: .note .warning}
+If you are using Ruby version 3.0.0 or higher, step 5 [may fail](https://github.com/github/pages-gem/issues/752). You may fix it by adding `webrick` to your dependencies: `bundle add webrick`
+
 {: .note .info}
 Pass the `--livereload` option to `serve` to automatically refresh the page with each change you make to the source files: `bundle exec jekyll serve --livereload`