diff -r 3d3b4ac369f2 -r cabac7dfc621 mercurial/exchange.py
--- a/mercurial/exchange.py	Mon Jan 25 11:37:02 2016 -0800
+++ b/mercurial/exchange.py	Fri Jan 22 16:31:50 2016 -0800
@@ -717,6 +717,8 @@
     cgpart = bundler.newpart('changegroup', data=cg)
     if version is not None:
         cgpart.addparam('version', version)
+    if 'treemanifest' in pushop.repo.requirements:
+        cgpart.addparam('treemanifest', '1')
     def handlereply(op):
         """extract addchangegroup returns from server reply"""
         cgreplies = op.records.getreplies(cgpart.id)