diff --git a/README.md b/README.md
index 9fa212a..3648028 100644
--- a/README.md
+++ b/README.md
@@ -150,6 +150,11 @@ class ApplicationController < ActionController::Base
 end
 ```
 
+Both these methods may lead to a `DoubleRenderError` if you use Rails and
+actually did not call `authorize` since most controllers already call `render`
+beforehand.
+
+
 ## Scopes
 
 Often, you will want to have some kind of view listing records which a