diff --git a/libs/ardour/ardour/rc_configuration_vars.h b/libs/ardour/ardour/rc_configuration_vars.h
index b6d6c80b50..681c51a32c 100644
--- a/libs/ardour/ardour/rc_configuration_vars.h
+++ b/libs/ardour/ardour/rc_configuration_vars.h
@@ -142,7 +142,7 @@ CONFIG_VARIABLE (std::string, monitor_bus_preferred_bundle, "monitor-bus-preferr
 CONFIG_VARIABLE (bool, quieten_at_speed, "quieten-at-speed", true)
 
 CONFIG_VARIABLE (bool, link_send_and_route_panner, "link-send-and-route-panner", true)
-CONFIG_VARIABLE (std::string, midi_audition_synth_uri, "midi-audition-synth-uri", "")
+CONFIG_VARIABLE (std::string, midi_audition_synth_uri, "midi-audition-synth-uri", "@default@")
 
 /* click */