diff --git a/Lib/test/test_charmapcodec.py b/Lib/test/test_charmapcodec.py
index d5981be8bd7..5e4055eec94 100644
--- a/Lib/test/test_charmapcodec.py
+++ b/Lib/test/test_charmapcodec.py
@@ -27,27 +27,27 @@ codecname = 'testcodec'
 
 class CharmapCodecTest(unittest.TestCase):
     def test_constructorx(self):
-        self.assertEquals(str('abc', codecname), 'abc')
-        self.assertEquals(str('xdef', codecname), 'abcdef')
-        self.assertEquals(str('defx', codecname), 'defabc')
-        self.assertEquals(str('dxf', codecname), 'dabcf')
-        self.assertEquals(str('dxfx', codecname), 'dabcfabc')
+        self.assertEquals(str(b'abc', codecname), 'abc')
+        self.assertEquals(str(b'xdef', codecname), 'abcdef')
+        self.assertEquals(str(b'defx', codecname), 'defabc')
+        self.assertEquals(str(b'dxf', codecname), 'dabcf')
+        self.assertEquals(str(b'dxfx', codecname), 'dabcfabc')
 
     def test_encodex(self):
-        self.assertEquals('abc'.encode(codecname), 'abc')
-        self.assertEquals('xdef'.encode(codecname), 'abcdef')
-        self.assertEquals('defx'.encode(codecname), 'defabc')
-        self.assertEquals('dxf'.encode(codecname), 'dabcf')
-        self.assertEquals('dxfx'.encode(codecname), 'dabcfabc')
+        self.assertEquals('abc'.encode(codecname), b'abc')
+        self.assertEquals('xdef'.encode(codecname), b'abcdef')
+        self.assertEquals('defx'.encode(codecname), b'defabc')
+        self.assertEquals('dxf'.encode(codecname), b'dabcf')
+        self.assertEquals('dxfx'.encode(codecname), b'dabcfabc')
 
     def test_constructory(self):
-        self.assertEquals(str('ydef', codecname), 'def')
-        self.assertEquals(str('defy', codecname), 'def')
-        self.assertEquals(str('dyf', codecname), 'df')
-        self.assertEquals(str('dyfy', codecname), 'df')
+        self.assertEquals(str(b'ydef', codecname), 'def')
+        self.assertEquals(str(b'defy', codecname), 'def')
+        self.assertEquals(str(b'dyf', codecname), 'df')
+        self.assertEquals(str(b'dyfy', codecname), 'df')
 
     def test_maptoundefined(self):
-        self.assertRaises(UnicodeError, str, 'abc\001', codecname)
+        self.assertRaises(UnicodeError, str, b'abc\001', codecname)
 
 def test_main():
     test.test_support.run_unittest(CharmapCodecTest)
diff --git a/Lib/test/testcodec.py b/Lib/test/testcodec.py
index 7ac9203d3cd..e7f836be704 100644
--- a/Lib/test/testcodec.py
+++ b/Lib/test/testcodec.py
@@ -36,7 +36,7 @@ def getregentry():
 decoding_map = codecs.make_identity_dict(range(256))
 decoding_map.update({
         0x78: "abc", # 1-n decoding mapping
-        "abc": 0x0078,# 1-n encoding mapping
+        str8("abc"): 0x0078,# 1-n encoding mapping
         0x01: None,   # decoding mapping to <undefined>
         0x79: "",    # decoding mapping to <remove character>
 })