--- a/mercurial/wireprotov2peer.py	Sun Nov 10 07:30:14 2019 -0800
+++ b/mercurial/wireprotov2peer.py	Fri Nov 08 11:19:20 2019 -0800
@@ -472,7 +472,7 @@
             )
 
         headers = {
-            r'Accept': redirect.mediatype,
+            'Accept': redirect.mediatype,
         }
 
         req = self._requestbuilder(pycompat.strurl(redirect.url), None, headers)