diff --git a/gtk2_ardour/gain_meter.cc b/gtk2_ardour/gain_meter.cc
index 67f9ce9370..c2e4a43858 100644
--- a/gtk2_ardour/gain_meter.cc
+++ b/gtk2_ardour/gain_meter.cc
@@ -864,7 +864,7 @@ GainMeterBase::update_meters()
 	}
 }
 
-void GainMeterBase::color_handler(bool dpi)
+void GainMeterBase::color_handler(bool /* dpi */)
 {
 	setup_meters();
 }