The digest name is text.
diff --git a/OpenSSL/test/test_crypto.py b/OpenSSL/test/test_crypto.py
index 6b48282..a80b88d 100644
--- a/OpenSSL/test/test_crypto.py
+++ b/OpenSSL/test/test_crypto.py
@@ -2441,7 +2441,7 @@
         # certificate unrelated to priv_key, used to trigger an error
         bad_cert = load_certificate(FILETYPE_PEM, server_cert_pem)
 
-        for digest in (b('md5'), b('sha1')):
+        for digest in ['md5', 'sha1']:
             sig = sign(priv_key, content, digest)
 
             # Verify the signature of content, will throw an exception if error.