diff --git a/Lib/test/test_multibytecodec.py b/Lib/test/test_multibytecodec.py
index de27339..b6557f3 100644
--- a/Lib/test/test_multibytecodec.py
+++ b/Lib/test/test_multibytecodec.py
@@ -136,11 +136,19 @@
         self.assertRaises(UnicodeDecodeError, decoder.decode, '', True)
         self.assertEqual(decoder.decode('B@$'), u'\u4e16')
 
+class Test_StreamReader(unittest.TestCase):
+    def test_bug1728403(self):
+        try:
+            open(TESTFN, 'w').write('\xa1')
+            f = codecs.open(TESTFN, encoding='cp949')
+            self.assertRaises(UnicodeDecodeError, f.read, 2)
+        finally:
+            os.unlink(TESTFN)
 
 class Test_StreamWriter(unittest.TestCase):
     if len(u'\U00012345') == 2: # UCS2
         def test_gb18030(self):
-            s= StringIO.StringIO()
+            s = StringIO.StringIO()
             c = codecs.getwriter('gb18030')(s)
             c.write(u'123')
             self.assertEqual(s.getvalue(), '123')