diff --git a/lib/models/room.js b/lib/models/room.js
index 7fe3ea5c8..46c07fb90 100644
--- a/lib/models/room.js
+++ b/lib/models/room.js
@@ -59,7 +59,7 @@ function synthesizeReceipt(userId, event, receiptType) {
  * @prop {string} roomId The ID of this room.
  * @prop {string} name The human-readable display name for this room.
  * @prop {Array<MatrixEvent>} timeline The ordered list of message events for
- * this room.
+ * this room, with the oldest event at index 0.
  * @prop {object} tags Dict of room tags; the keys are the tag name and the values
  * are any metadata associated with the tag - e.g. { "fav" : { order: 1 } }
  * @prop {RoomState} oldState The state of the room at the time of the oldest