diff --git a/docs/en/docs/release-notes.md b/docs/en/docs/release-notes.md
index 1c0f83c34..1071ff4de 100644
--- a/docs/en/docs/release-notes.md
+++ b/docs/en/docs/release-notes.md
@@ -2,6 +2,7 @@
 
 ## Latest changes
 
+* Add note in docs on order in Pydantic Unions. PR [#1591](https://github.com/tiangolo/fastapi/pull/1591) by [@kbanc](https://github.com/kbanc).
 * Improve support for tests in editor. PR [#1699](https://github.com/tiangolo/fastapi/pull/1699).
 * Pin dependencies. PR [#1697](https://github.com/tiangolo/fastapi/pull/1697).
 * Update isort to version 5.x.x. PR [#1670](https://github.com/tiangolo/fastapi/pull/1670) by [@asheux](https://github.com/asheux).