diff --git a/docs/about/release-notes.md b/docs/about/release-notes.md
index ed089754..a72e227a 100644
--- a/docs/about/release-notes.md
+++ b/docs/about/release-notes.md
@@ -45,11 +45,17 @@ documentation][rtd-docs] for details.
 [upstream]: https://github.com/rtfd/sphinx_rtd_theme/
 [rtd-docs]: ../user-guide/styling-your-docs.md#readthedocs
 
-#### Update `mkdocs` theme to bootswatch 4.1.3 (#1563)
+#### Update `mkdocs` theme to Bootswatch 4.1.3 (#1563)
 
 The `mkdocs` theme now supports all the features of [Bootswatch 4.1]. Note that
 the [dropdowns] used in the navigation only support one level of nesting. If
 your global navigation uses more than one level, things will likely be broken.
+Additionaly, 2 filenames were changed in this update. If you are using a theme
+which inherits from the `mkdocs` theme, the theme developer may need to update
+these filenames as follows.
+
+   css/bootstrap-custom.min.css => css/bootstrap.min.css
+   js/bootstrap-3.0.3.min.js => js/bootstrap.min.js
 
 [Bootswatch 4.1]: https://getbootstrap.com/docs/4.1/getting-started/introduction/
 [dropdowns]: https://getbootstrap.com/docs/4.1/components/navs/#pills-with-dropdowns