diff --git a/src/calibre/gui2/languages.py b/src/calibre/gui2/languages.py
index 3398081c5f..d7f34df1b4 100644
--- a/src/calibre/gui2/languages.py
+++ b/src/calibre/gui2/languages.py
@@ -9,7 +9,7 @@ __docformat__ = 'restructuredtext en'
 
 from calibre.gui2.complete import MultiCompleteComboBox
 from calibre.utils.localization import lang_map
-from calibre.utils.icu import sort_key
+from calibre.utils.icu import sort_key, lower
 
 class LanguagesEdit(MultiCompleteComboBox):
 
@@ -22,7 +22,7 @@ class LanguagesEdit(MultiCompleteComboBox):
         self.names_with_commas = [x for x in self._lang_map.itervalues() if ',' in x]
         self.comma_map = {k:k.replace(',', '|') for k in self.names_with_commas}
         self.comma_rmap = {v:k for k, v in self.comma_map.iteritems()}
-        self._rmap = {v:k for k,v in self._lang_map.iteritems()}
+        self._rmap = {lower(v):k for k,v in self._lang_map.iteritems()}
 
         all_items = sorted(self._lang_map.itervalues(),
             key=sort_key)
@@ -46,7 +46,7 @@ class LanguagesEdit(MultiCompleteComboBox):
             ans = []
             for name in vals:
                 if name:
-                    code = self._rmap.get(name, None)
+                    code = self._rmap.get(lower(name), None)
                     if code is not None:
                         ans.append(code)
             return ans
@@ -66,7 +66,7 @@ class LanguagesEdit(MultiCompleteComboBox):
         bad = []
         for name in vals:
             if name:
-                code = self._rmap.get(name, None)
+                code = self._rmap.get(lower(name), None)
                 if code is None:
                     bad.append(name)
         return bad