diff -r 1ceb91974dc4 Lib/urllib/request.py
--- a/Lib/urllib/request.py	Sat Apr 30 01:30:57 2016 +0000
+++ b/Lib/urllib/request.py	Sat Apr 30 17:54:10 2016 +0800
@@ -1271,6 +1271,7 @@
 
         # will parse host:port
         h = http_class(host, timeout=req.timeout, **http_conn_args)
+        h.set_debuglevel(self._debuglevel)
 
         headers = dict(req.unredirected_hdrs)
         headers.update(dict((k, v) for k, v in req.headers.items()