diff --git a/libs/ardour/ardour/rc_configuration_vars.h b/libs/ardour/ardour/rc_configuration_vars.h
index 39a080faae..146f91dd68 100644
--- a/libs/ardour/ardour/rc_configuration_vars.h
+++ b/libs/ardour/ardour/rc_configuration_vars.h
@@ -186,3 +186,4 @@ CONFIG_VARIABLE (bool, show_zoom_tools, "show-zoom-tools", true)
 CONFIG_VARIABLE (bool, widget_prelight, "widget-prelight", true)
 CONFIG_VARIABLE (std::string, mixer_strip_visibility, "mixer-strip-visibility", "PhaseInvert,SoloSafe,SoloIsolated,Group,MeterPoint")
 CONFIG_VARIABLE (bool, allow_non_quarter_pulse, "allow-non-quarter-pulse", false)
+CONFIG_VARIABLE (bool, show_region_gain, "show-region-gain", false)