--- a/mercurial/sshpeer.py	Sun Feb 11 13:09:16 2018 -0800
+++ b/mercurial/sshpeer.py	Sun Feb 11 13:23:26 2018 -0800
@@ -220,7 +220,7 @@
 
     # Generate a random token to help identify responses to version 2
     # upgrade request.
-    token = bytes(uuid.uuid4())
+    token = pycompat.sysbytes(str(uuid.uuid4()))
     upgradecaps = [
         ('proto', wireprotoserver.SSHV2),
     ]