diff --git a/src/experimental/demo/convex_hull_demo.scad b/src/experimental/demo/convex_hull_demo.scad
index d9a2f8f8..404268f9 100644
--- a/src/experimental/demo/convex_hull_demo.scad
+++ b/src/experimental/demo/convex_hull_demo.scad
@@ -1,3 +1,4 @@
+use <hull_polyline2d.scad>;
 use <experimental/tri_bisectors.scad>;
 use <experimental/convex_hull.scad>;
 use <shape_starburst.scad>;