diff --git a/src/github.com/matrix-org/dendrite/syncapi/sync/notifier.go b/src/github.com/matrix-org/dendrite/syncapi/sync/notifier.go
index a739e9126..db9fbf164 100644
--- a/src/github.com/matrix-org/dendrite/syncapi/sync/notifier.go
+++ b/src/github.com/matrix-org/dendrite/syncapi/sync/notifier.go
@@ -107,23 +107,22 @@ func (n *Notifier) WaitForEvents(req syncRequest) types.StreamPosition {
 
 	// TODO: v1 /events 'peeking' has an 'explicit room ID' which is also tracked,
 	//       but given we don't do /events, let's pretend it doesn't exist.
-	for {
-		// In a guard, check if the /sync request should block, and block it until we get woken up
-		n.currPosMutex.RLock()
-		currentPos := n.currPos
-		n.currPosMutex.RUnlock()
 
-		// TODO: We increment the stream position for any event, so it's possible that we return immediately
-		//       with a pos which contains no new events for this user. We should probably re-wait for events
-		//       automatically in this case.
-		if req.since != currentPos {
-			return currentPos
-		}
+	// In a guard, check if the /sync request should block, and block it until we get woken up
+	n.currPosMutex.RLock()
+	currentPos := n.currPos
+	n.currPosMutex.RUnlock()
 
-		// wait to be woken up, and then re-check the stream position
-		req.log.WithField("user_id", req.userID).Info("Waiting for event")
-		n.blockUser(req.userID)
+	// TODO: We increment the stream position for any event, so it's possible that we return immediately
+	//       with a pos which contains no new events for this user. We should probably re-wait for events
+	//       automatically in this case.
+	if req.since != currentPos {
+		return currentPos
 	}
+
+	// wait to be woken up, and then re-check the stream position
+	req.log.WithField("user_id", req.userID).Info("Waiting for event")
+	return n.blockUser(req.userID)
 }
 
 // Load the membership states required to notify users correctly.
@@ -161,17 +160,15 @@ func (n *Notifier) wakeupUser(userID string, newPos types.StreamPosition) {
 	stream.Broadcast(newPos) // wakeup all goroutines Wait()ing on this stream
 }
 
-func (n *Notifier) blockUser(userID string) {
+func (n *Notifier) blockUser(userID string) types.StreamPosition {
 	stream := n.fetchUserStream(userID, true)
-	stream.Wait()
+	return stream.Wait()
 }
 
 // fetchUserStream retrieves a stream unique to the given user. If makeIfNotExists is true,
 // a stream will be made for this user if one doesn't exist and it will be returned. This
 // function does not wait for data to be available on the stream.
 func (n *Notifier) fetchUserStream(userID string, makeIfNotExists bool) *UserStream {
-	// There is a bit of a locking dance here, we want to lock the mutex protecting the map
-	// but NOT the Cond that we may be returning/creating.
 	n.userStreamsMutex.Lock()
 	defer n.userStreamsMutex.Unlock()
 	stream, ok := n.userStreams[userID]