diff -r e17b8466857e -r 9dc36df78403 mercurial/commands.py
--- a/mercurial/commands.py	Thu May 04 21:47:03 2017 +0200
+++ b/mercurial/commands.py	Fri May 05 17:09:47 2017 +0200
@@ -1393,10 +1393,11 @@
     if complevel is not None:
         compopts['level'] = complevel
 
-    cg = changegroup.getchangegroup(repo, 'bundle', outgoing, version=cgversion)
-
-    bundle2.writebundle(ui, cg, fname, bversion, compression=bcompression,
-                        compopts=compopts)
+
+    contentopts = {'cg.version': cgversion}
+    bundle2.writenewbundle(ui, repo, 'bundle', fname, bversion, outgoing,
+                           contentopts, compression=bcompression,
+                           compopts=compopts)
 
 @command('cat',
     [('o', 'output', '',