--- a/mercurial/hgweb/hgweb_mod.py	Sun Oct 15 00:05:43 2017 -0400
+++ b/mercurial/hgweb/hgweb_mod.py	Sun Oct 15 00:38:33 2017 -0400
@@ -378,7 +378,7 @@
                     req.env.get('X-HgHttp2', '')):
                     req.drain()
                 else:
-                    req.headers.append(('Connection', 'Close'))
+                    req.headers.append((r'Connection', r'Close'))
                 req.respond(inst, protocol.HGTYPE,
                             body='0\n%s\n' % inst)
                 return ''