diff --git a/openscad/zippy_cover.scad b/openscad/zippy_cover.scad
index 677e766..3c0a802 100644
--- a/openscad/zippy_cover.scad
+++ b/openscad/zippy_cover.scad
@@ -1,6 +1,6 @@
 difference()
 {
-	cylinder(5, 11, 11, $fn=360, center = true);
+	cylinder(5, 12, 12, $fn=360, center = true);
 	translate([0, 0, 1.5])
 	cylinder(5, 10.5, 10.5, $fn=360, center = true);
 }