diff --git a/guides/source/4_2_release_notes.md b/guides/source/4_2_release_notes.md
index 684bd286bcd1c3e47a804f0c17b4c8e13048a2d2..8a59007420ee1c8445f075744110799a4baf4f10 100644
--- a/guides/source/4_2_release_notes.md
+++ b/guides/source/4_2_release_notes.md
@@ -227,6 +227,17 @@ restore the old behavior.
 If you do this, be sure to configure your firewall properly such that only
 trusted machines on your network can access your development server.
 
+### Changed status option symbols for `render`
+
+Due to a [change in Rack](https://github.com/rack/rack/commit/be28c6a2ac152fe4adfbef71f3db9f4200df89e8), the symbols that the `render` method accepts for the `:status` option have changed:
+
+- 306: `:reserved` has been removed.
+- 413: `:request_entity_too_large` has been renamed to `:payload_too_large`.
+- 414: `:request_uri_too_long` has been renamed to `:uri_too_long`.
+- 416: `:requested_range_not_satisfiable` has been renamed to `:range_not_satisfiable`.
+
+Keep in mind that if calling `render` with an unknown symbol, the response status will default to 500.
+
 ### HTML Sanitizer
 
 The HTML sanitizer has been replaced with a new, more robust, implementation