diff -r 40df727b6f4f -r 7eedbd5d4880 mercurial/configitems.py
--- a/mercurial/configitems.py	Wed Jan 17 14:13:46 2018 +0100
+++ b/mercurial/configitems.py	Wed Jan 17 16:41:44 2018 +0100
@@ -431,6 +431,9 @@
 coreconfigitem('experimental', 'bundle2.pushback',
     default=False,
 )
+coreconfigitem('experimental', 'bundle2.stream',
+    default=False,
+)
 coreconfigitem('experimental', 'bundle2lazylocking',
     default=False,
 )