diff --git a/rbtools/postreview.py b/rbtools/postreview.py
--- a/rbtools/postreview.py
+++ b/rbtools/postreview.py
@@ -258,8 +258,8 @@ class ReviewBoardHTTPPasswordMgr(urllib2.HTTPPasswordMgr):
     def __init__(self, reviewboard_url):
         self.passwd  = {}
         self.rb_url  = reviewboard_url
-        self.rb_user = None
-        self.rb_pass = None
+        self.rb_user = options.http_username
+        self.rb_pass = options.http_password
 
     def find_user_password(self, realm, uri):
         if uri.startswith(self.rb_url):
@@ -2637,6 +2637,12 @@ def parse_options(args):
                       dest="diff_filename", default=None,
                       help='upload an existing diff file, instead of '
                            'generating a new diff')
+    parser.add_option("--http-username",
+                      dest="http_username", default=None, metavar="USERNAME",
+                      help='the username for basic HTTP authentication')
+    parser.add_option("--http-password",
+                      dest="http_password", default=None, metavar="PASSWORD",
+                      help='the password for basic HTTP authentication')
 
     (globals()["options"], args) = parser.parse_args(args)