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 14f625891..db271710c 100644
--- a/src/github.com/matrix-org/dendrite/syncapi/sync/notifier.go
+++ b/src/github.com/matrix-org/dendrite/syncapi/sync/notifier.go
@@ -100,7 +100,9 @@ func (n *Notifier) OnNewEvent(ev *gomatrixserverlib.Event, userID string, pos ty
 	}
 }
 
-// WaitForEvents blocks until there are new events for this request.
+// WaitForEvents blocks until there are events for this request after sincePos.
+// In particular, it will return immediately if there are already events after
+// sincePos for the request, but otherwise blocks waiting for new events.
 func (n *Notifier) WaitForEvents(req syncRequest, sincePos types.StreamPosition) types.StreamPosition {
 	// Do what synapse does: https://github.com/matrix-org/synapse/blob/v0.20.0/synapse/notifier.py#L298
 	// - Bucket request into a lookup map keyed off a list of joined room IDs and separately a user ID
diff --git a/src/github.com/matrix-org/dendrite/syncapi/sync/requestpool.go b/src/github.com/matrix-org/dendrite/syncapi/sync/requestpool.go
index 31ecc503f..7ef09323c 100644
--- a/src/github.com/matrix-org/dendrite/syncapi/sync/requestpool.go
+++ b/src/github.com/matrix-org/dendrite/syncapi/sync/requestpool.go
@@ -122,6 +122,9 @@ func (rp *RequestPool) OnIncomingSyncRequest(req *http.Request, device *authtype
 func (rp *RequestPool) makeNotifyChannel(syncReq syncRequest, sincePos types.StreamPosition) chan types.StreamPosition {
 	notified := make(chan types.StreamPosition)
 
+	// TODO(#303): We need to ensure that WaitForEvents gets properly cancelled
+	// when the request is finished, or use some other mechanism to ensure we
+	// don't leak goroutines here
 	go (func() {
 		currentPos := rp.notifier.WaitForEvents(syncReq, sincePos)
 		notified <- currentPos