diff --git a/src/stem_supports/tines.scad b/src/stem_supports/tines.scad
index 56ff739..fd99720 100644
--- a/src/stem_supports/tines.scad
+++ b/src/stem_supports/tines.scad
@@ -4,14 +4,14 @@ include <../stems/cherry.scad>
 module centered_tines(stem_support_height) {
   if ($key_length < 2) {
     translate([0,0,$stem_support_height / 2]) {
-      cube([total_key_width(), 0.5, $stem_support_height], center = true);
+      cube([total_key_width() -$wall_thickness/2, 0.5, $stem_support_height], center = true);
     }
   }
 
   translate([0,0,$stem_support_height / 2]) {
     cube([
       1,
-      total_key_height(),
+      total_key_height() -$wall_thickness/2,
       $stem_support_height
     ],
     center = true);