diff --git a/index.bs b/index.bs
index 0af8e25..2356ba4 100644
--- a/index.bs
+++ b/index.bs
@@ -1266,7 +1266,7 @@ The [=timeline offset=] associated with the playback changes since the last sent
 
 The {{stalled}} event needs to fire at the associated {{HTMLMediaElement}} instance.
 
-More than 350ms pass since the last [=remote-playback-state-event=] message
+More than 250ms pass since the last [=remote-playback-state-event=] message
   and any of the following attributes observably change since the last
   [=remote-playback-state-event=] message. Any new continuously changing
   attributes fall under this rule.
@@ -1274,6 +1274,9 @@ More than 350ms pass since the last [=remote-playback-state-event=] message
 * {{HTMLMediaElement/played|HTMLMediaElement.played}}
 * {{HTMLMediaElement/currentTime|HTMLMediaElement.currentTime}}
 
+NOTE: A media element is required to fire a {{HTMLMediaElement/timeupdate}}
+event every 250ms or sooner.
+
 : remote-playback-id
 :: The ID of the remote playback whose state has changed.