diff --git a/src/c3nav/site/static/site/js/c3nav.js b/src/c3nav/site/static/site/js/c3nav.js
index 2d5108a1..adbb4f71 100644
--- a/src/c3nav/site/static/site/js/c3nav.js
+++ b/src/c3nav/site/static/site/js/c3nav.js
@@ -1555,7 +1555,7 @@ L.SquareGridLayer = L.Layer.extend({
     },
 
     _updateGrid: function(map) {
-        if (!this.cols.length) return;
+        if (!this.cols || this.cols.length) return;
         var mapSize = map.getSize(),
             sidebarStart = $('#sidebar').outerWidth() + 15,
             searchHeight = $('#search').outerHeight() + 10,