diff --git a/templates/owner.html b/templates/owner.html
index 13ab6f2..e02d314 100644
--- a/templates/owner.html
+++ b/templates/owner.html
@@ -1,41 +1,41 @@
 {% extends "layout.html" %}
 
 {% block content %}
 <h2>Tables owned by {{ name }} ({{ name|owner }})</h2>
 <table class="table table-striped table-condensed table-bordered tablesort">
   <thead>
     <tr>
       <th>Server</th>
       <th>Schema</th>
       <th>Table</th>
       <th data-sort-method="number" data-sort-default>Size</th>
       <th data-sort-method="number">Rows</th>
     </tr>
   </thead>
   <tbody>
     {% for r in usage|sort(attribute='host') %}
     <tr>
       <td>{{ r.host }}</td>
       <td>{{ r.table_schema }}</td>
       <td>{{ r.table_name }}</td>
-      <td class="number" data-sort="{{ r.total_bytes }}">{{ r.total_bytes|filesizeformat }}</td>
+      <td class="number" data-sort="{{ r.total_bytes|default(0, true) }}">{{ r.total_bytes|default(0, true)|filesizeformat }}</td>
       <td class="number">{{ r.row_count|int }}</td>
     </tr>
     {% endfor %}
   </tbody>
 </table>
 {% endblock %}
 
 {% block js %}
 {{ super() }}
 <script src="https://tools-static.wmflabs.org/cdnjs/ajax/libs/tablesort/5.0.0/tablesort.min.js"></script>
 <script src="https://tools-static.wmflabs.org/cdnjs/ajax/libs/tablesort/5.0.0/src/sorts/tablesort.number.js"></script>
 <script>
   $(document).ready(function() {
     $('table.tablesort').each(function(idx, elm) {
       new Tablesort(elm, {descending: true});
     });
   });
 </script>
 {% endblock %}
 {# vim:sw=2:ts=2:sts=2:et: #}