diff --git a/sfc/slicer.py b/sfc/slicer.py
index e161277..871f089 100755
--- a/sfc/slicer.py
+++ b/sfc/slicer.py
@@ -217,17 +217,18 @@ else:
 if height is not None and height < 0 and z_levels[-1] > height:
 	z_levels.append(height - z_off)
 
-z_levels[-1] += end
-
-for next_z in z_levels:
+for i in range(0, len(z_levels)):
+	next_z = z_levels[i]
 	wires = shape.slice(Base.Vector(0, 0, 1), next_z + epsilon)
+	if i == len(z_levels) - 1:
+		next_z += end
 	if z_step is None or last_z is None or last_z - z_step <= next_z:
 		dump_level(wires, next_z + z_off)
 	else:
 		d = last_z - next_z
 		n = int(d // z_step) + 1
-		for i in range(0, n):
-			dump_level(wires, last_z - (i + 1) * (d / n) + z_off)
+		for j in range(0, n):
+			dump_level(wires, last_z - (j + 1) * (d / n) + z_off)
 	last_z = next_z
 	
 #