diff --git a/src/calibre/gui2/complete.py b/src/calibre/gui2/complete.py
index 5aa3d5af9b..a0c0307425 100644
--- a/src/calibre/gui2/complete.py
+++ b/src/calibre/gui2/complete.py
@@ -9,7 +9,7 @@ __docformat__ = 'restructuredtext en'
 from PyQt4.Qt import (QLineEdit, QAbstractListModel, Qt,
         QApplication, QCompleter)
 
-from calibre.utils.icu import sort_key, lower
+from calibre.utils.icu import sort_key
 from calibre.gui2 import NONE
 from calibre.gui2.widgets import EnComboBox, LineEditECM
 from calibre.utils.config_base import tweaks
@@ -24,12 +24,11 @@ class CompleteModel(QAbstractListModel):
     def set_items(self, items):
         items = [unicode(x.strip()) for x in items]
         if len(items) < tweaks['completion_change_to_ascii_sorting']:
-            self.items = sorted(items, key=lambda x: sort_key(x))
+            self.items = sorted(items, key=sort_key)
             self.sorting = QCompleter.UnsortedModel
         else:
             self.items = sorted(items, key=lambda x:x.lower())
             self.sorting = QCompleter.CaseInsensitivelySortedModel
-        self.lowered_items = [lower(x) for x in self.items]
         self.reset()
 
     def rowCount(self, *args):