diff --git a/gtk2_ardour/route_ui.cc b/gtk2_ardour/route_ui.cc
index ab83206a8c..6a79ce0282 100644
--- a/gtk2_ardour/route_ui.cc
+++ b/gtk2_ardour/route_ui.cc
@@ -62,7 +62,7 @@ using namespace Gtkmm2ext;
 using namespace ARDOUR;
 using namespace PBD;
 
-uint32_t RouteUI::_max_invert_buttons = 4;
+uint32_t RouteUI::_max_invert_buttons = 3;
 
 RouteUI::RouteUI (ARDOUR::Session* sess)
 	: AxisView(sess)