diff --git a/src/components/structures/RoomView.js b/src/components/structures/RoomView.js
index accf96f349..9fbdb51f11 100644
--- a/src/components/structures/RoomView.js
+++ b/src/components/structures/RoomView.js
@@ -493,6 +493,17 @@ module.exports = React.createClass({
             return;
         }
 
+        if (this.props.ConferenceHandler &&
+            member.userId === this.props.ConferenceHandler.getConferenceUserIdForRoom(member.roomId)) {
+            this._updateConfCallNotification();
+        }
+
+        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);
         this._updateAutoComplete();
@@ -506,12 +517,7 @@ module.exports = React.createClass({
                 joining: false
             });
         }
-
-        if (this.props.ConferenceHandler &&
-            member.userId === this.props.ConferenceHandler.getConferenceUserIdForRoom(member.roomId)) {
-            this._updateConfCallNotification();
-        }
-    },
+    }, 500),
 
     _hasUnsentMessages: function(room) {
         return this._getUnsentMessages(room).length > 0;
diff --git a/src/ratelimitedfunc.js b/src/ratelimitedfunc.js
index 453669b477..ed892f4eac 100644
--- a/src/ratelimitedfunc.js
+++ b/src/ratelimitedfunc.js
@@ -14,6 +14,14 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+/**
+ * 'debounces' a function to only execute every n milliseconds.
+ * Useful when react-sdk gets many, many events but only wants
+ * to update the interface once for all of them.
+ *
+ * Note that the function must not take arguments, since the args
+ * could be different for each invocarion of the function.
+ */
 module.exports = function(f, minIntervalMs) {
     this.lastCall = 0;
     this.scheduledCall = undefined;