gistfile1.diff

diff --git a/server/devpi_server/replica.py b/server/devpi_server/replica.py
index e8aef55..69e5a27 100644
--- a/server/devpi_server/replica.py
+++ b/server/devpi_server/replica.py
@@ -6,6 +6,7 @@ import time
 from pyramid.httpexceptions import HTTPNotFound, HTTPAccepted
 from pyramid.view import view_config
 from pyramid.response import Response
+from webob.headers import EnvironHeaders
 
 from .keyfs import load, loads, dump, get_write_file_ensure_dir
 from .log import thread_push_log, threadlog
@@ -256,9 +257,12 @@ def proxy_write_to_master(xom, request):
     with threadlog.around("info", "relaying: %s %s", request.method,
     url):
         try:
+            headers = EnvironHeaders({})
+            headers.update(request.headers)
+            headers.pop('host', None)
             r = http.request(request.method, url,
                              data=request.body,
-                             headers=request.headers,
+                             headers=headers,
                              allow_redirects=False)
         except http.Errors as e:
             raise UpstreamError("proxy-write-to-master %s: %s" % (url, e))