diff --git a/lib/util/toplist.js b/lib/util/toplist.js
index <HASH>..<HASH> 100644
--- a/lib/util/toplist.js
+++ b/lib/util/toplist.js
@@ -46,10 +46,18 @@ module.exports = {
 
   },
   getLargestPages: function(pages, limit) {
+
     pages.sort(function(page, thatPage) {
-      return thatPage.yslow.pageWeight.v - page.yslow.pageWeight.v;
+
+      // if YSlow fails but we collect other data
+      // we have the page object but no YSlow
+      if (thatPage.yslow && page.yslow) {
+        return thatPage.yslow.pageWeight.v - page.yslow.pageWeight.v;
+      }
+      return 0;
     });
 
+
     return pages.slice(0, limit < pages.length ? limit : pages.length);
safe check for pages without yslow