diff --git a/testdata/scad/bugs/horn-torus.scad b/testdata/scad/bugs/horn-torus.scad
new file mode 100644
index 00000000..f93a3645
--- /dev/null
+++ b/testdata/scad/bugs/horn-torus.scad
@@ -0,0 +1,5 @@
+// This model causes a CGAL assertion in CGAL_Nef_polyhedron3(CGAL_Polyhedron) constructor.
+// One cause of this error could be that the grid handling in PolySet degenerated the original
+// mesh into a non-manifold one.
+
+rotate_extrude($fn = 24) translate ([ 1, 0, 0 ]) circle (r = 1);