diff --git a/lib/http-api.js b/lib/http-api.js
index edddab27e..42db907f3 100644
--- a/lib/http-api.js
+++ b/lib/http-api.js
@@ -21,7 +21,7 @@ module.exports.PREFIX_V1 = "/_matrix/client/api/v1";
  * A constant representing the URI path for version 2 alpha of the Client-Server
  * HTTP API.
  */
-module.exports.PREFIX_V2_ALPHA_PREFIX = "/_matrix/client/v2_alpha";
+module.exports.PREFIX_V2_ALPHA = "/_matrix/client/v2_alpha";
 
 /**
  * Construct a MatrixHttpApi.
diff --git a/lib/models/room.js b/lib/models/room.js
index 8d82c5585..1a682a62a 100644
--- a/lib/models/room.js
+++ b/lib/models/room.js
@@ -85,25 +85,9 @@ utils.inherits(Room, EventEmitter);
 Room.prototype.addEventsToTimeline = function(events, toStartOfTimeline) {
     var stateContext = toStartOfTimeline ? this.oldState : this.currentState;
     for (var i = 0; i < events.length; i++) {
-        // set sender and target properties
-        events[i].sender = stateContext.getSentinelMember(
-            events[i].getSender()
-        );
-        if (events[i].getType() === "m.room.member") {
-            events[i].target = stateContext.getSentinelMember(
-                events[i].getStateKey()
-            );
-        }
-
+        setEventMetadata(events[i], stateContext, toStartOfTimeline);
         // modify state
         if (events[i].isState()) {
-            // room state has no concept of 'old' or 'current', but we want the
-            // room state to regress back to previous values if toStartOfTimeline
-            // is set, which means inspecting prev_content if it exists. This
-            // is done by toggling the forwardLooking flag.
-            if (toStartOfTimeline) {
-                events[i].forwardLooking = false;
-            }
             stateContext.setStateEvents([events[i]]);
         }
         // TODO: pass through filter to see if this should be added to the timeline.
@@ -146,6 +130,12 @@ Room.prototype.addEvents = function(events, duplicateStrategy) {
                 for (var j = 0; j < this.timeline.length; j++) {
                     if (this.timeline[j].getId() === events[i].getId()) {
                         if (duplicateStrategy === "replace") {
+                            // still need to set the right metadata on this event
+                            setEventMetadata(
+                                events[i],
+                                this.currentState,
+                                false
+                            );
                             this.timeline[j] = events[i];
                             // skip the insert so we don't add this event twice.
                             // Don't break in case we replace multiple events.
@@ -187,6 +177,27 @@ Room.prototype.recalculate = function(userId) {
     }
 };
 
+function setEventMetadata(event, stateContext, toStartOfTimeline) {
+    // set sender and target properties
+    event.sender = stateContext.getSentinelMember(
+        event.getSender()
+    );
+    if (event.getType() === "m.room.member") {
+        event.target = stateContext.getSentinelMember(
+            event.getStateKey()
+        );
+    }
+    if (event.isState()) {
+        // room state has no concept of 'old' or 'current', but we want the
+        // room state to regress back to previous values if toStartOfTimeline
+        // is set, which means inspecting prev_content if it exists. This
+        // is done by toggling the forwardLooking flag.
+        if (toStartOfTimeline) {
+            event.forwardLooking = false;
+        }
+    }
+}
+
 /**
  * This is an internal method. Calculates the name of the room from the current
  * room state.