diff -r d227451ee280 -r ab9121fda8d2 mercurial/wireproto.py
--- a/mercurial/wireproto.py	Fri Jun 30 03:44:10 2017 +0200
+++ b/mercurial/wireproto.py	Fri Jun 30 03:44:11 2017 +0200
@@ -771,7 +771,7 @@
 
     if proto.name == 'http':
         caps.append('httpheader=%d' %
-                    repo.ui.configint('server', 'maxhttpheaderlen', 1024))
+                    repo.ui.configint('server', 'maxhttpheaderlen'))
         if repo.ui.configbool('experimental', 'httppostargs', False):
             caps.append('httppostargs')