diff --git a/src/surface/sf_splines.scad b/src/surface/sf_splines.scad
index 5ec914d8..4b61d160 100644
--- a/src/surface/sf_splines.scad
+++ b/src/surface/sf_splines.scad
@@ -18,10 +18,9 @@ function sf_splines(ctrl_pts, row_spline, column_spline) =
 		    for(r = 0; r < leng_ctrl_pts; r = r + 1)
 				row_spline(ctrl_pts[r])
 		],
-        leng_r_pts0 = len(r_pts[0]),
-        leng_r_pts = len(r_pts)
+        leng_r_pts0 = len(r_pts[0])
 	)
     m_transpose([
         for(c = 0; c < leng_r_pts0; c = c + 1)
-            cspline([for(r = 0; r < leng_r_pts; r = r + 1) r_pts[r][c]]) 
+        cspline([for(pts = r_pts) pts[c]]) 
     ]);