diff --git a/src/__private__/__trapezium.scad b/src/__private__/__trapezium.scad
index 3dddac87..5715ff5e 100644
--- a/src/__private__/__trapezium.scad
+++ b/src/__private__/__trapezium.scad
@@ -3,7 +3,7 @@ function __trapezium(length, h, round_r) =
         r_half_trapezium = __half_trapezium(length / 2, h, round_r),
         to = len(r_half_trapezium) - 1,
         l_half_trapezium = [
-            for(i = [0:to]) 
+            for(i = 0; i <= to; i = i + 1)
                 let(pt = r_half_trapezium[to - i])
                 [-pt[0], pt[1]]
         ]