diff -r e9d325cfe071 -r 664d6f6c2a48 mercurial/localrepo.py
--- a/mercurial/localrepo.py	Fri Jun 23 13:49:34 2017 +0200
+++ b/mercurial/localrepo.py	Tue Jul 04 10:17:14 2017 -0400
@@ -432,9 +432,6 @@
             'aggressivemergedeltas', False)
         self.svfs.options['aggressivemergedeltas'] = aggressivemergedeltas
         self.svfs.options['lazydeltabase'] = not scmutil.gddeltaconfig(self.ui)
-        chainspan = self.ui.configbytes('experimental', 'maxdeltachainspan', -1)
-        if 0 <= chainspan:
-            self.svfs.options['maxdeltachainspan'] = chainspan
 
         for r in self.requirements:
             if r.startswith('exp-compression-'):