diff --git a/src/experimental/_impl/_convex_center_p_impl.scad b/src/experimental/_impl/_convex_center_p_impl.scad
index 0bd9d2ab..d8f957dd 100644
--- a/src/experimental/_impl/_convex_center_p_impl.scad
+++ b/src/experimental/_impl/_convex_center_p_impl.scad
@@ -1,2 +1,2 @@
 function _sum(lt, leng, i = 0) =
-    i == leng ? [0, 0] : lt[i] + _sum(lt, leng, i + 1);
+    i == leng ? [0, 0, 0] : lt[i] + _sum(lt, leng, i + 1);