diff -r 88b6b37eb7cf Lib/locale.py
--- a/Lib/locale.py	Thu Dec 19 22:32:40 2013 +0200
+++ b/Lib/locale.py	Fri Dec 20 13:18:17 2013 +0200
@@ -1284,7 +1284,7 @@
     'korean':                               'ko_KR.eucKR',
     'korean.euc':                           'ko_KR.eucKR',
     'ks':                                   'ks_IN.UTF-8',
-    'ks_in@devanagari':                     'ks_IN@devanagari.UTF-8',
+    'ks_in':                                'ks_IN.UTF-8',
     'kw':                                   'kw_GB.ISO8859-1',
     'kw_gb':                                'kw_GB.ISO8859-1',
     'kw_gb.iso88591':                       'kw_GB.ISO8859-1',
@@ -1444,7 +1444,8 @@
     'rw':                                   'rw_RW.ISO8859-1',
     'rw_rw':                                'rw_RW.ISO8859-1',
     'rw_rw.iso88591':                       'rw_RW.ISO8859-1',
-    'sd':                                   'sd_IN@devanagari.UTF-8',
+    'sd':                                   'sd_IN.UTF-8',
+    'sd_in':                                'sd_IN.UTF-8',
     'se_no':                                'se_NO.UTF-8',
     'serbocroatian':                        'sr_RS.UTF-8@latin',
     'sh':                                   'sr_RS.UTF-8@latin',
diff -r 88b6b37eb7cf Lib/test/test_locale.py
--- a/Lib/test/test_locale.py	Thu Dec 19 22:32:40 2013 +0200
+++ b/Lib/test/test_locale.py	Fri Dec 20 13:18:17 2013 +0200
@@ -422,6 +422,20 @@
         self.check('ca_ES@valencia', 'ca_ES.ISO8859-1@valencia')
         self.check('ca@valencia', 'ca_ES.ISO8859-1@valencia')
 
+    def test_devanagari_modifier(self):
+        self.check('ks_IN.UTF-8@devanagari', 'ks_IN.UTF-8@devanagari')
+        self.check('ks_IN@devanagari', 'ks_IN.UTF-8@devanagari')
+        self.check('ks@devanagari', 'ks_IN.UTF-8@devanagari')
+        self.check('ks_IN.UTF-8', 'ks_IN.UTF-8')
+        self.check('ks_IN', 'ks_IN.UTF-8')
+        self.check('ks', 'ks_IN.UTF-8')
+        self.check('sd_IN.UTF-8@devanagari', 'sd_IN.UTF-8@devanagari')
+        self.check('sd_IN@devanagari', 'sd_IN.UTF-8@devanagari')
+        self.check('sd@devanagari', 'sd_IN.UTF-8@devanagari')
+        self.check('sd_IN.UTF-8', 'sd_IN.UTF-8')
+        self.check('sd_IN', 'sd_IN.UTF-8')
+        self.check('sd', 'sd_IN.UTF-8')
+
 
 class TestMiscellaneous(unittest.TestCase):
     def test_getpreferredencoding(self):
diff -r 88b6b37eb7cf Tools/i18n/makelocalealias.py
--- a/Tools/i18n/makelocalealias.py	Thu Dec 19 22:32:40 2013 +0200
+++ b/Tools/i18n/makelocalealias.py	Fri Dec 20 13:18:17 2013 +0200
@@ -23,6 +23,9 @@
         if line[:1] == '#':
             continue
         locale, alias = line.split()
+        if '.' in alias.partition('@')[2]:
+            # Ignore illegal entities which contain encoding after modifier
+            continue
         # Strip ':'
         if locale[-1] == ':':
             locale = locale[:-1]