diff --git a/gtk2_ardour/visibility_group.h b/gtk2_ardour/visibility_group.h
index 940b8bcc52..20be7dcf72 100644
--- a/gtk2_ardour/visibility_group.h
+++ b/gtk2_ardour/visibility_group.h
@@ -41,7 +41,7 @@ public:
 		Gtk::Widget *,
 		std::string const &,
 		std::string const &,
-		bool visible = 0,
+		bool visible = false,
 		boost::function<boost::optional<bool> ()> = 0
 		);