diff --git a/doc/manual/src/release-notes/rl-next.md b/doc/manual/src/release-notes/rl-next.md
index 80eed9397..7dd8387d8 100644
--- a/doc/manual/src/release-notes/rl-next.md
+++ b/doc/manual/src/release-notes/rl-next.md
@@ -1,5 +1,18 @@
 # Release X.Y (202?-??-??)
 
+* A number of "default" flake output attributes have been
+  renamed. These are:
+
+  * `defaultPackage.<system>` → `packages.<system>.default`
+  * `defaultApps.<system>` → `apps.<system>.default`
+  * `defaultTemplate` → `templates.default`
+  * `defaultBundler.<system>` → `bundlers.<system>.default`
+  * `overlay` → `overlays.default`
+  * `devShell.<system>` → `devShells.<system>.default`
+
+  The old flake output attributes still work, but `nix flake check`
+  will warn about them.
+
 * `nix bundle` breaking API change now supports bundlers of the form
   `bundler.<system>.<name>= derivation: another-derivation;`. This supports
   additional functionality to inspect evaluation information during bundling. A