--- a/mercurial/wireproto.py	Fri Jun 30 03:42:43 2017 +0200
+++ b/mercurial/wireproto.py	Fri Jun 30 03:44:06 2017 +0200
@@ -608,7 +608,7 @@
         if v is not None:
             return v
 
-    return ui.configbool('server', 'bundle1', True)
+    return ui.configbool('server', 'bundle1')
 
 def supportedcompengines(ui, proto, role):
     """Obtain the list of supported compression engines for a request."""