diff --git a/src/calibre/gui2/tag_browser/model.py b/src/calibre/gui2/tag_browser/model.py
index 89b42950e0..9c73c20bed 100644
--- a/src/calibre/gui2/tag_browser/model.py
+++ b/src/calibre/gui2/tag_browser/model.py
@@ -11,6 +11,7 @@ __docformat__ = 'restructuredtext en'
 import traceback, cPickle, copy
 from itertools import repeat
 from collections import defaultdict
+from functools import partial
 
 from PyQt4.Qt import (QAbstractItemModel, QIcon, QVariant, QFont, Qt,
         QMimeData, QModelIndex, pyqtSignal, QObject)
@@ -832,11 +833,9 @@ class TagsModel(QAbstractItemModel): # {{{
                         if lower(t.name).find(self.filter_categories_by) >= 0]
 
         tb_categories = self.db.field_metadata
-        y = tweaks['tag_browser_category_order']
-        deforder = y.get('*', 100)
-        order = defaultdict(lambda : deforder)
-        order.update(y)
-        tb_keys = sorted(tb_categories.iterkeys(), key=order.get)
+        order = tweaks['tag_browser_category_order']
+        defvalue = order.get('*', 100)
+        tb_keys = sorted(tb_categories.keys(), key=lambda x: order.get(x, defvalue))
         for category in tb_keys:
             if category in data: # The search category can come and go
                 self.row_map.append(category)