diff -r 7126d8b8e0e6 -r a61287a95dc3 mercurial/wireprotov2server.py
--- a/mercurial/wireprotov2server.py	Mon Jan 13 17:14:19 2020 -0500
+++ b/mercurial/wireprotov2server.py	Mon Jan 13 17:15:14 2020 -0500
@@ -8,7 +8,6 @@
 
 import collections
 import contextlib
-import hashlib
 
 from .i18n import _
 from .node import (
@@ -31,6 +30,7 @@
 from .interfaces import util as interfaceutil
 from .utils import (
     cborutil,
+    hashutil,
     stringutil,
 )
 
@@ -858,7 +858,7 @@
 
         cacher.adjustcachekeystate(state)
 
-        hasher = hashlib.sha1()
+        hasher = hashutil.sha1()
         for chunk in cborutil.streamencode(state):
             hasher.update(chunk)