diff --git a/notebook/static/tree/js/notebooklist.js b/notebook/static/tree/js/notebooklist.js
index 860632785..fb8104ec3 100644
--- a/notebook/static/tree/js/notebooklist.js
+++ b/notebook/static/tree/js/notebooklist.js
@@ -71,12 +71,14 @@ define([
           }
 
           if (b.size === undefined) {
-             return (ascending) ? 1 : -1;
+             return (ascending) ? -1 : 1;
           }
 
           if (a.size > b.size) {
             return (ascending) ? 1 : -1;
-          } else {
+          }
+
+          if (b.size > a.size) {
             return (ascending) ? -1 : 1;
           }
 
@@ -864,7 +866,7 @@ define([
         // Add in the date that the file was last modified
         item.find(".item_modified").text(utils.format_datetime(model.last_modified));
         item.find(".item_modified").attr("title", moment(model.last_modified).format("YYYY-MM-DD HH:mm"));
-        item.find(".file_size").text(model.size || '');
+        item.find(".file_size").html(model.size || " ");
     };