diff --git a/rack-protection/README.md b/rack-protection/README.md
index 21a13aa7..b6d7e5d1 100644
--- a/rack-protection/README.md
+++ b/rack-protection/README.md
@@ -43,6 +43,7 @@ Prevented by:
 * `Rack::Protection::JsonCsrf`
 * `Rack::Protection::RemoteReferrer` (not included by `use Rack::Protection`)
 * `Rack::Protection::RemoteToken`
+* `Rack::Protection::HttpOrigin`
 
 ## Cross Site Scripting