diff --git a/shelf.scad b/shelf.scad
index f75cc92..dd398de 100644
--- a/shelf.scad
+++ b/shelf.scad
@@ -1,5 +1,9 @@
 include <Round-Anything/polyround.scad>
 
+module _end_of_customizer_vars() {}
+
+$fn = $preview ? 30 : 60;
+
 module jar() {
     cylinder(100, 40, 40);
 }