diff --git a/gtk2_ardour/route_ui.cc b/gtk2_ardour/route_ui.cc
index f46450a0bc..9a64ca8aa3 100644
--- a/gtk2_ardour/route_ui.cc
+++ b/gtk2_ardour/route_ui.cc
@@ -512,7 +512,7 @@ RouteUI::rec_enable_press(GdkEventButton* ev)
 }
 
 bool
-RouteUI::rec_enable_release (GdkEventButton* ev)
+RouteUI::rec_enable_release (GdkEventButton*)
 {
 	return true;
 }