diff --git a/docs/en/docs/release-notes.md b/docs/en/docs/release-notes.md
index 443ae7111..353788c76 100644
--- a/docs/en/docs/release-notes.md
+++ b/docs/en/docs/release-notes.md
@@ -13,6 +13,7 @@ hide:
 
 ### Fixes
 
+* 🐛 Reenable `allow_arbitrary_types` when only 1 argument is used on the API endpoint. PR [#13694](https://github.com/fastapi/fastapi/pull/13694) by [@rmawatson](https://github.com/rmawatson).
 * 🐛 Fix `inspect.getcoroutinefunction()` can break testing with `unittest.mock.patch()`. PR [#14022](https://github.com/fastapi/fastapi/pull/14022) by [@secrett2633](https://github.com/secrett2633).
 
 ### Refactors