diff --git a/src/experimental/demo/voronoi_cells_demo.scad b/src/experimental/demo/voronoi_cells_demo.scad
index 68ef4a44..ed6c0f9a 100644
--- a/src/experimental/demo/voronoi_cells_demo.scad
+++ b/src/experimental/demo/voronoi_cells_demo.scad
@@ -6,17 +6,7 @@ xs1 = rands(-20, 20, 15);
 ys1 = rands(-20, 20, 15);
 points = [for(i = [0:len(xs1) - 1]) [xs1[i], ys1[i]]];
 
-function default_region_size(points) = 
-    let(
-        xs = [for(p = points) p[0]],
-        ys = [for(p = points) abs(p[1])]
-    )
-    max([(max(xs) -  min(xs) / 2), (max(ys) -  min(ys)) / 2]);
-
-size = default_region_size(points);  
-region_shape = shape_square(size, corner_r = size / 10);
-
-cells = voronoi_cells(points, region_shape);
+cells = voronoi_cells(points);
 for(i = [0:len(points) - 1]) {
     pt = points[i];
     cell = cells[i];
diff --git a/src/experimental/voronoi_cells.scad b/src/experimental/voronoi_cells.scad
index 355de7d4..40015b38 100644
--- a/src/experimental/voronoi_cells.scad
+++ b/src/experimental/voronoi_cells.scad
@@ -2,10 +2,10 @@ use <experimental/_impl/_voronoi2d_cells_impl.scad>;
 use <experimental/convex_intersection_for.scad>;
 use <shape_square.scad>;
 
-function voronoi_cells(points, region_shape) = 
+function voronoi_cells(points) = 
     let(
         size = _default_region_size(points),
-        shape = is_undef(region_shape) ? shape_square(size) : region_shape,
+        shape = shape_square(size),
         regions_lt = [
             for(p = points) 
                 _cells_lt_before_intersection(shape, size, points, p)