}
-static DBusHandlerResult msg_signal_filter_impl(AVAHI_GCC_UNUSED DBusConnection *c, DBusMessage *m, void *userdata) {
+static DBusHandlerResult msg_signal_filter_impl(AVAHI_GCC_UNUSED DBusConnection *c, DBusMessage *m, AVAHI_GCC_UNUSED void *userdata) {
DBusError error;
dbus_error_init(&error);