--- a/mercurial/wireprotoserver.py	Mon Mar 26 13:57:22 2018 -0700
+++ b/mercurial/wireprotoserver.py	Mon Mar 26 11:00:16 2018 -0700
@@ -546,7 +546,7 @@
 
     res.status = b'200 OK'
     res.headers[b'Content-Type'] = FRAMINGTYPE
-    stream = wireprotoframing.stream()
+    stream = wireprotoframing.stream(2)
 
     if isinstance(rsp, wireprototypes.bytesresponse):
         action, meta = reactor.onbytesresponseready(stream,