diff --git a/src/points.js b/src/points.js
index 14f2ffb..b38cf12 100644
--- a/src/points.js
+++ b/src/points.js
@@ -38,10 +38,12 @@ const render_zone = exports._render_zone = (zone_name, zone, anchor, global_key)
 
     // column layout
 
-    for (const [col_name, col] of Object.entries(cols)) {
+    for (let [col_name, col] of Object.entries(cols)) {
 
         // column-level sanitization
 
+        col = col || {}
+
         a.detect_unexpected(
             col,
             `points.zones.${zone_name}.columns.${col_name}`,