diff --git a/src/shape_arc.scad b/src/shape_arc.scad
index 444b2935..9be452ff 100644
--- a/src/shape_arc.scad
+++ b/src/shape_arc.scad
@@ -40,14 +40,14 @@ function shape_arc(radius, angle, width, width_mode = "LINE_CROSS") =
         points = concat(
             // outer arc path
             [__ra_to_xy(_edge_r_begin(r_outer, angles[0], a_step, m), angles[0])],
-            [
+            m > n ? [] : [
                 for(i = [m:n]) 
                     __ra_to_xy(r_outer, a_step * i)
             ],
             [__ra_to_xy(_edge_r_end(r_outer, angles[1], a_step, n), angles[1])],
             // inner arc path
             [__ra_to_xy(_edge_r_end(r_inner, angles[1], a_step, n), angles[1])],
-            [
+            m > n ? [] : [
                 for(i = [m:n]) 
                     let(idx = (n + (m - i)))
                     __ra_to_xy(r_inner, a_step * idx)