diff --git a/gtk2_ardour/ardour_button.cc b/gtk2_ardour/ardour_button.cc
index 2da0aaa4b8..f4aa1225f0 100644
--- a/gtk2_ardour/ardour_button.cc
+++ b/gtk2_ardour/ardour_button.cc
@@ -543,7 +543,7 @@ ArdourButton::set_corner_radius (float r)
 void
 ArdourButton::on_size_request (Gtk::Requisition* req)
 {
-	req->height = req->height = 0;
+	req->width = req->height = 0;
 	CairoWidget::on_size_request (req);
 
 	if (_diameter == 0) {