--- a/mercurial/hgweb/request.py	Sat Feb 17 01:09:56 2018 -0500
+++ b/mercurial/hgweb/request.py	Sat Feb 17 01:11:48 2018 -0500
@@ -121,7 +121,8 @@
             elif isinstance(status, int):
                 status = statusmessage(status)
 
-            self.server_write = self._start_response(status, self.headers)
+            self.server_write = self._start_response(
+                pycompat.sysstr(status), self.headers)
             self._start_response = None
             self.headers = []
         if body is not None: