diff --git a/paths.scad b/paths.scad
index c8f404f..4bd8877 100644
--- a/paths.scad
+++ b/paths.scad
@@ -259,7 +259,7 @@ module extrude_2d_hollow(wall=2, height=50, twist=90, slices=60, center=undef, o
 // Example:
 //   poly = [[-10,0], [-3,-5], [3,-5], [10,0], [0,-30]];
 //   extrude_2dpath_along_spiral(poly, h=200, r=50, twist=1080, $fn=36);
-module extrude_2dpath_along_spiral(polyline, h, r, twist=360, center=undef, orient=ORIENT_Z, anchor=CENTER) {
+module extrude_2dpath_along_spiral(polyline, h, r, twist=360, center=undef, orient=ORIENT_Z, anchor=BOTTOM) {
 	pline_count = len(polyline);
 	steps = ceil(segs(r)*(twist/360));
 
@@ -275,7 +275,7 @@ module extrude_2dpath_along_spiral(polyline, h, r, twist=360, center=undef, orie
 				polyline, [
 					matrix4_xrot(90),
 					matrix4_zrot(a),
-					matrix4_translate([dx, dy, dz])
+					matrix4_translate([dx, dy, dz-h/2])
 				]
 			)
 		) for (pt = pts) pt