diff --git a/Lib/test/test_multibytecodec_support.py b/Lib/test/test_multibytecodec_support.py
index 36245b7..9aa764a 100644
--- a/Lib/test/test_multibytecodec_support.py
+++ b/Lib/test/test_multibytecodec_support.py
@@ -244,22 +244,6 @@
 
                 self.assertEqual(ostream.getvalue(), self.tstring[0])
 
-if len(u'\U00012345') == 2: # ucs2 build
-    _unichr = unichr
-    def unichr(v):
-        if v >= 0x10000:
-            return _unichr(0xd800 + ((v - 0x10000) >> 10)) + \
-                   _unichr(0xdc00 + ((v - 0x10000) & 0x3ff))
-        else:
-            return _unichr(v)
-    _ord = ord
-    def ord(c):
-        if len(c) == 2:
-            return 0x10000 + ((_ord(c[0]) - 0xd800) << 10) + \
-                          (ord(c[1]) - 0xdc00)
-        else:
-            return _ord(c)
-
 class TestBase_Mapping(unittest.TestCase):
     pass_enctest = []
     pass_dectest = []
@@ -282,7 +266,8 @@
             self._test_mapping_file_plain()
 
     def _test_mapping_file_plain(self):
-        unichrs = lambda s: u''.join(map(unichr, map(eval, s.split('+'))))
+        _unichr = lambda c: eval("u'\\U%08x'" % int(c, 16))
+        unichrs = lambda s: u''.join(_unichr(c) for c in s.split('+'))
         urt_wa = {}
 
         for line in self.open_mapping_file():
@@ -307,7 +292,7 @@
                 continue
 
             unich = unichrs(data[1])
-            if ord(unich) == 0xfffd or unich in urt_wa:
+            if unich == u'\ufffd' or unich in urt_wa:
                 continue
             urt_wa[unich] = csetch