diff --git a/case/top.scad b/case/top.scad
index 30fffe9..caee717 100644
--- a/case/top.scad
+++ b/case/top.scad
@@ -150,19 +150,19 @@ module top_case(key_switch_sizes, pcb_screw_holes) {
         module walls() {
             /* Upper */
             translate([-wall_width, keyboard_length, 0])
-            cube([keyboard_width + 2 * wall_width, wall_width, key_switch_height], false);
+            cube([keyboard_width + 2 * wall_width, wall_width, key_switch_height - wall_width], false);
 
             /* Right */
             translate([keyboard_width, -wall_width, 0])
-            cube([wall_width, keyboard_length + 2 * wall_width, key_switch_height], false);
+            cube([wall_width, keyboard_length + 2 * wall_width, key_switch_height - wall_width], false);
 
             /* Lower */
             translate([-wall_width, -wall_width, 0])
-            cube([keyboard_width + 2 * wall_width, wall_width, key_switch_height], false);
+            cube([keyboard_width + 2 * wall_width, wall_width, key_switch_height - wall_width], false);
 
             /* Left */
             translate([-wall_width, -wall_width, 0])
-            cube([wall_width, keyboard_length + 2 * wall_width, key_switch_height], false);
+            cube([wall_width, keyboard_length + 2 * wall_width, key_switch_height - wall_width], false);
         }
 
         module body() {