diff --git a/tracker/tablecell.py b/tracker/tablecell.py
index afb6468..36bc9b2 100644
--- a/tracker/tablecell.py
+++ b/tracker/tablecell.py
@@ -1,7 +1,6 @@
-# Copyright 2016 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style
-# license that can be found in the LICENSE file or at
-# https://developers.google.com/open-source/licenses/bsd
+# Copyright 2016 The Chromium Authors
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
 
 """Classes that generate value cells in the issue list table."""
 
@@ -221,7 +220,7 @@
     values = [_make_issue_view(issue.project_name, _kw["config"],
                                 _kw["viewable_iids_set"], ref_issue)
               for ref_issue in ref_issues]
-    values.sort(key=lambda x: (x.closed, x.id))
+    values.sort(key=lambda x: (bool(x.closed), x.id))
     table_view_helpers.TableCell.__init__(
         self, table_view_helpers.CELL_TYPE_ISSUES, values, sort_values=False)
 
@@ -235,7 +234,7 @@
     values = [_make_issue_view(issue.project_name, _kw["config"],
                                 _kw["viewable_iids_set"], ref_issue)
               for ref_issue in ref_issues]
-    values.sort(key=lambda x: (x.closed, x.id))
+    values.sort(key=lambda x: (bool(x.closed), x.id))
     table_view_helpers.TableCell.__init__(
         self, table_view_helpers.CELL_TYPE_ISSUES, values, sort_values=False)