diff --git a/requests/sessions.py b/requests/sessions.py
index 06e17d4b..2aae6e40 100644
--- a/requests/sessions.py
+++ b/requests/sessions.py
@@ -155,6 +155,7 @@ class SessionRedirectMixin(object):
 
             extract_cookies_to_jar(prepared_request._cookies,
                                    prepared_request, resp.raw)
+            prepared_request._cookies.update(self.cookies)
             prepared_request.prepare_cookies(prepared_request._cookies)
 
             resp = self.send(