Use PyBytes_ for 3.x compatibility
diff --git a/OpenSSL/test/test_crypto.py b/OpenSSL/test/test_crypto.py
index 1fcb543..55c42f1 100644
--- a/OpenSSL/test/test_crypto.py
+++ b/OpenSSL/test/test_crypto.py
@@ -1486,7 +1486,7 @@
         the algorithm used to sign the certificate.
         """
         cert = load_certificate(FILETYPE_PEM, self.pemData)
-        self.assertEqual(cert.get_signature_algorithm(), "sha1WithRSAEncryption")
+        self.assertEqual(cert.get_signature_algorithm(), b("sha1WithRSAEncryption"))
 
 
     def test_get_undefined_signature_algorithm(self):