Panel plugin warning on session start

The following warning message appears in the session log on a fresh boot:

(wrapper-2.0:499): xfce4-notification-plugin-WARNING **: 14:37:47.115: Unable to check for unread messages: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.xfce.Notifyd was not provided by any .service files

Notification logging is not enabled.

Version: 0.8.2