diff --git a/src/components/structures/RoomView.js b/src/components/structures/RoomView.js
index 6d35f76529..9fbdb51f11 100644
--- a/src/components/structures/RoomView.js
+++ b/src/components/structures/RoomView.js
@@ -501,6 +501,8 @@ module.exports = React.createClass({
         this._updateRoomMembers();
     },
 
+    // rate limited because a power level change will emit an event for every
+    // member in the room.
     _updateRoomMembers: new rate_limited_func(function() {
         // a member state changed in this room, refresh the tab complete list
         this.tabComplete.loadEntries(this.state.room);