diff --git a/pdagent/thirdparty/httpswithverify.py b/pdagent/thirdparty/httpswithverify.py
index 702c6833..1470dae0 100644
--- a/pdagent/thirdparty/httpswithverify.py
+++ b/pdagent/thirdparty/httpswithverify.py
@@ -121,6 +121,7 @@ def connect(self):
             # proxy server. See: httplib.HTTPConnection._tunnel()
             end_host = self._tunnel_host
             self.sock = sock
+            self._tunnel_headers = { "Host": end_host }
             self._tunnel()
 
         # require server certificate to be provided, and pass along