diff --git a/gtk2_ardour/mixer_ui.cc b/gtk2_ardour/mixer_ui.cc
index e907a8a93d..42fa7d1054 100644
--- a/gtk2_ardour/mixer_ui.cc
+++ b/gtk2_ardour/mixer_ui.cc
@@ -1199,6 +1199,8 @@ Mixer_UI::group_flags_changed (void* src, RouteGroup* group)
 	}
 
 	in_group_row_change = false;
+
+	_group_tabs->set_dirty ();
 }
 
 void