diff --git a/src/github.com/matrix-org/dendrite/appservice/consumers/roomserver.go b/src/github.com/matrix-org/dendrite/appservice/consumers/roomserver.go
index ac366913..b3584dfb 100644
--- a/src/github.com/matrix-org/dendrite/appservice/consumers/roomserver.go
+++ b/src/github.com/matrix-org/dendrite/appservice/consumers/roomserver.go
@@ -179,7 +179,12 @@ func (s *OutputRoomEventConsumer) filterRoomserverEvents(
 // appserviceIsInterestedInEvent returns a boolean depending on whether a given
 // event falls within one of a given application service's namespaces.
 func (s *OutputRoomEventConsumer) appserviceIsInterestedInEvent(ctx context.Context, event gomatrixserverlib.Event, appservice config.ApplicationService) bool {
-	// Check room_id and sender of the event
+	// No reason to queue events if they'll never be sent to the application
+	// service
+	if appservice.URL == "" {
+		return false
+	}
+
 	if appservice.IsInterestedInUserID(event.Sender()) ||
 		appservice.IsInterestedInRoomID(event.RoomID()) {
 		return true
diff --git a/src/github.com/matrix-org/dendrite/clientapi/routing/register.go b/src/github.com/matrix-org/dendrite/clientapi/routing/register.go
index 34d237d5..bfecec5d 100644
--- a/src/github.com/matrix-org/dendrite/clientapi/routing/register.go
+++ b/src/github.com/matrix-org/dendrite/clientapi/routing/register.go
@@ -337,8 +337,9 @@ func UsernameMatchesMultipleExclusiveNamespaces(
 ) bool {
 	// Check namespaces and see if more than one match
 	matchCount := 0
+	userID := userutil.MakeUserID(username, cfg.Matrix.ServerName)
 	for _, appservice := range cfg.Derived.ApplicationServices {
-		if appservice.IsInterestedInUserID(username) {
+		if appservice.IsInterestedInUserID(userID) {
 			if matchCount++; matchCount > 1 {
 				return true
 			}