diff --git a/actionview/app/assets/javascripts/README.md b/actionview/app/assets/javascripts/README.md
index 185dddc7e5712..b74fa1afad7c4 100644
--- a/actionview/app/assets/javascripts/README.md
+++ b/actionview/app/assets/javascripts/README.md
@@ -23,6 +23,8 @@ Note that the `data` attributes this library adds are a feature of HTML5. If you
     
     yarn add rails-ujs
 
+Ensure that `.yarnclean` does not include `assets` if you use [yarn autoclean](https://yarnpkg.com/lang/en/docs/cli/autoclean/).
+
 ## Usage
 
 ### Asset pipeline