diff --git a/crates/ruma-common/CHANGELOG.md b/crates/ruma-common/CHANGELOG.md
index 6038b2af..313b3b3f 100644
--- a/crates/ruma-common/CHANGELOG.md
+++ b/crates/ruma-common/CHANGELOG.md
@@ -22,6 +22,9 @@ Breaking changes:
 * Fix the `RoomMessageEventContent::*_reply_plain` methods that now return a
   message with a `formatted_body`, according to the spec. Therefore, they only
   accept `OriginalRoomMessageEvent`s like their HTML counterparts.
+* Update the `state_key` field of state events to be of a different type
+  depending on the content type. You now no longer need to validate manually
+  that `m.room.member` events have a user ID as their state key!
 
 Improvements: