Issue #4387: binascii now refuses to accept str as binary input.
diff --git a/Lib/test/test_zlib.py b/Lib/test/test_zlib.py
index f52aa5e..99c8dda 100644
--- a/Lib/test/test_zlib.py
+++ b/Lib/test/test_zlib.py
@@ -48,11 +48,11 @@
         self.assertEqual(zlib.adler32('spam'), 72286642)
 
     def test_same_as_binascii_crc32(self):
-        foo = 'abcdefghijklmnop'
+        foo = b'abcdefghijklmnop'
         crc = 2486878355
         self.assertEqual(binascii.crc32(foo), crc)
         self.assertEqual(zlib.crc32(foo), crc)
-        self.assertEqual(binascii.crc32('spam'), zlib.crc32('spam'))
+        self.assertEqual(binascii.crc32(b'spam'), zlib.crc32(b'spam'))