diff -r e3cd724231ff -r 8e0358024a36 mercurial/bundle2.py
--- a/mercurial/bundle2.py	Sat Sep 16 11:09:08 2017 -0400
+++ b/mercurial/bundle2.py	Fri Sep 15 18:38:36 2017 -0400
@@ -1444,7 +1444,7 @@
     part = bundler.newpart('changegroup', data=cg.getchunks())
     part.addparam('version', cg.version)
     if 'clcount' in cg.extras:
-        part.addparam('nbchanges', str(cg.extras['clcount']),
+        part.addparam('nbchanges', '%d' % cg.extras['clcount'],
                       mandatory=False)
     if opts.get('phases') and repo.revs('%ln and secret()',
                                         outgoing.missingheads):
@@ -1520,7 +1520,7 @@
         part = bundle.newpart('changegroup', data=cg.getchunks())
         part.addparam('version', cg.version)
         if 'clcount' in cg.extras:
-            part.addparam('nbchanges', str(cg.extras['clcount']),
+            part.addparam('nbchanges', '%d' % cg.extras['clcount'],
                           mandatory=False)
         chunkiter = bundle.getchunks()
     else: