diff --git a/lib/models/event-timeline.js b/lib/models/event-timeline.js
index 343b3fbed..5c1545286 100644
--- a/lib/models/event-timeline.js
+++ b/lib/models/event-timeline.js
@@ -234,23 +234,29 @@ EventTimeline.prototype.setNeighbouringTimeline = function(neighbour, direction)
 EventTimeline.prototype.addEvent = function(event, atStart) {
     var stateContext = atStart ? this._startState : this._endState;
 
-    EventTimeline.setEventMetadata(event, stateContext, atStart);
+    // only call setEventMetadata on the unfiltered timelineSets
+    var timelineSet = this.getTimelineSet();
+    if (timelineSet.room &&
+        timelineSet.room.getUnfilteredTimelineSet() === timelineSet)
+    {
+        EventTimeline.setEventMetadata(event, stateContext, atStart);
 
-    // modify state
-    if (event.isState()) {
-        stateContext.setStateEvents([event]);
-        // it is possible that the act of setting the state event means we
-        // can set more metadata (specifically sender/target props), so try
-        // it again if the prop wasn't previously set. It may also mean that
-        // the sender/target is updated (if the event set was a room member event)
-        // so we want to use the *updated* member (new avatar/name) instead.
-        //
-        // However, we do NOT want to do this on member events if we're going
-        // back in time, else we'll set the .sender value for BEFORE the given
-        // member event, whereas we want to set the .sender value for the ACTUAL
-        // member event itself.
-        if (!event.sender || (event.getType() === "m.room.member" && !atStart)) {
-            EventTimeline.setEventMetadata(event, stateContext, atStart);
+        // modify state
+        if (event.isState()) {
+            stateContext.setStateEvents([event]);
+            // it is possible that the act of setting the state event means we
+            // can set more metadata (specifically sender/target props), so try
+            // it again if the prop wasn't previously set. It may also mean that
+            // the sender/target is updated (if the event set was a room member event)
+            // so we want to use the *updated* member (new avatar/name) instead.
+            //
+            // However, we do NOT want to do this on member events if we're going
+            // back in time, else we'll set the .sender value for BEFORE the given
+            // member event, whereas we want to set the .sender value for the ACTUAL
+            // member event itself.
+            if (!event.sender || (event.getType() === "m.room.member" && !atStart)) {
+                EventTimeline.setEventMetadata(event, stateContext, atStart);
+            }
         }
     }