diff --git a/src/bend_extrude.scad b/src/bend_extrude.scad
index a6ef7f7f..0dd886b8 100644
--- a/src/bend_extrude.scad
+++ b/src/bend_extrude.scad
@@ -1,17 +1,16 @@
-module bend_extrude(size, angle, frags = 24) {
+module bend_extrude(size, thickness, angle, frags = 24) {
     x = size[0];
     y = size[1];
-    z = size[2];
     frag_width = x / frags ;
     frag_angle = angle / frags;
     half_frag_width = 0.5 * frag_width;
     half_frag_angle = 0.5 * frag_angle;
     r = half_frag_width / sin(half_frag_angle);
-    s =  (r - z) / r;
+    s =  (r - thickness) / r;
     
     module get_frag(i) {
         offsetX = i * frag_width;
-        linear_extrude(z, scale = [s, 1]) 
+        linear_extrude(thickness, scale = [s, 1]) 
             translate([-offsetX - half_frag_width, 0, 0]) 
                 intersection() {
                     children();