Use unicode (and bytes as appropriate)
diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
index 2421a6b..ffbd14d 100644
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -254,7 +254,7 @@
                          stdout=subprocess.PIPE,
                          cwd=tmpdir)
         normcase = os.path.normcase
-        self.assertEqual(normcase(p.stdout.read()), normcase(tmpdir))
+        self.assertEqual(normcase(p.stdout.read()), bytes(normcase(tmpdir)))
 
     def test_env(self):
         newenv = os.environ.copy()