diff --git a/readme.changes.md b/readme.changes.md
index 672088958f0e22e8bfbb908e93d3ac37ccbb523a..ce2fc98aa8bdcbe92eea3ef6959ba760555c3ddd 100644
--- a/readme.changes.md
+++ b/readme.changes.md
@@ -15,7 +15,6 @@
 - `id` is now required for all mutations. It must be unique per client;
   duplicate registration throws in production and replaces the previous
   registration in development (hot reload re-runs `define`).
-- mutation arguments must be JSON serializable (`Json[]`)
 - `handleUnauthenticated` and `onUnauthenticated` now receive a serializable
   `MutationAction` (`{ id, description, args }`) instead of a description string