diff --git a/dbus.go b/dbus.go
index e857bb3..002c80d 100644
--- a/dbus.go
+++ b/dbus.go
@@ -262,7 +262,7 @@ func dbusCreateSession(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	call, err := dbusCall("CreateSession", req.CWD, req.Backend, req.Model, req.Agent)
+	call, err := dbusCall("CreateSession", req.CWD, req.Backend, req.Model, req.Agent, "")
 	if err != nil {
 		writeJSON(w, http.StatusBadGateway, map[string]string{"error": err.Error()})
 		return