diff --git a/libmproxy/cmdline.py b/libmproxy/cmdline.py
index d8b6000cb..b1cbfa3a7 100644
--- a/libmproxy/cmdline.py
+++ b/libmproxy/cmdline.py
@@ -760,6 +760,21 @@ def mitmweb():
         action="store_true", dest="wdebug",
         help="Turn on mitmweb debugging"
     )
+    group.add_argument(
+        "--wsingleuser",
+        action="store", dest="wsingleuser", type=str,
+        metavar="USER",
+        help="""
+            Allows access to a a single user, specified in the form
+            username:password.
+        """
+    )
+    group.add_argument(
+        "--whtpasswd",
+        action="store", dest="whtpasswd", type=str,
+        metavar="PATH",
+        help="Allow access to users specified in an Apache htpasswd file."
+    )
 
     common_options(parser)
     group = parser.add_argument_group(
diff --git a/libmproxy/main.py b/libmproxy/main.py
index f6664924a..ef1357545 100644
--- a/libmproxy/main.py
+++ b/libmproxy/main.py
@@ -125,6 +125,9 @@ def mitmweb(args=None):  # pragma: no cover
     web_options.wdebug = options.wdebug
     web_options.wiface = options.wiface
     web_options.wport = options.wport
+    web_options.wsingleuser = options.wsingleuser
+    web_options.whtpasswd = options.whtpasswd
+    web_options.process_web_options(parser)
 
     server = get_server(web_options.no_server, proxy_config)
 
diff --git a/libmproxy/web/__init__.py b/libmproxy/web/__init__.py
index c48b3d09b..50c49e8db 100644
--- a/libmproxy/web/__init__.py
+++ b/libmproxy/web/__init__.py
@@ -3,6 +3,8 @@ import collections
 import tornado.ioloop
 import tornado.httpserver
 
+from netlib.http import authentication
+
 from .. import controller, flow
 from . import app
 
@@ -113,6 +115,9 @@ class Options(object):
         "wdebug",
         "wport",
         "wiface",
+        "wauthenticator",
+        "wsingleuser",
+        "whtpasswd",
     ]
 
     def __init__(self, **kwargs):
@@ -122,13 +127,30 @@ class Options(object):
             if not hasattr(self, i):
                 setattr(self, i, None)
 
+    def process_web_options(self, parser):
+        if self.wsingleuser or self.whtpasswd:
+            if self.wsingleuser:
+                if len(self.wsingleuser.split(':')) != 2:
+                    return parser.error(
+                        "Invalid single-user specification. Please use the format username:password"
+                    )
+                username, password = self.wsingleuser.split(':')
+                self.wauthenticator = authentication.PassManSingleUser(username, password)
+            elif self.whtpasswd:
+                try:
+                    self.wauthenticator = authentication.PassManHtpasswd(self.whtpasswd)
+                except ValueError as v:
+                    return parser.error(v.message)
+        else:
+            self.wauthenticator = None
+
 
 class WebMaster(flow.FlowMaster):
 
     def __init__(self, server, options):
         self.options = options
         super(WebMaster, self).__init__(server, WebState())
-        self.app = app.Application(self, self.options.wdebug)
+        self.app = app.Application(self, self.options.wdebug, self.options.wauthenticator)
         if options.rfile:
             try:
                 self.load_flows_file(options.rfile)
diff --git a/libmproxy/web/app.py b/libmproxy/web/app.py
index 958b86698..2c45a1dcc 100644
--- a/libmproxy/web/app.py
+++ b/libmproxy/web/app.py
@@ -4,6 +4,7 @@ import tornado.web
 import tornado.websocket
 import logging
 import json
+import base64
 
 from netlib.http import CONTENT_MISSING
 from .. import version, filt
@@ -40,7 +41,28 @@ class APIError(tornado.web.HTTPError):
     pass
 
 
-class RequestHandler(tornado.web.RequestHandler):
+class BasicAuth(object):
+    def set_auth_headers(self):
+        self.set_status(401)
+        self.set_header('WWW-Authenticate', 'Basic realm=MITMWeb')
+        self._transforms = []
+        self.finish()
+
+    def prepare(self):
+        wauthenticator = self.application.settings['wauthenticator']
+        if wauthenticator:
+            auth_header = self.request.headers.get('Authorization')
+            if auth_header is None or not auth_header.startswith('Basic '):
+                self.set_auth_headers()
+            else:
+                self.auth_decoded = base64.decodestring(auth_header[6:])
+                self.username, self.password = self.auth_decoded.split(':', 2)
+                if not wauthenticator.test(self.username, self.password):
+                    self.set_auth_headers()
+                    raise APIError(401, "Invalid username or password.")
+
+
+class RequestHandler(BasicAuth, tornado.web.RequestHandler):
 
     def set_default_headers(self):
         super(RequestHandler, self).set_default_headers()
@@ -100,7 +122,7 @@ class FiltHelp(RequestHandler):
         ))
 
 
-class WebSocketEventBroadcaster(tornado.websocket.WebSocketHandler):
+class WebSocketEventBroadcaster(BasicAuth, tornado.websocket.WebSocketHandler):
     # raise an error if inherited class doesn't specify its own instance.
     connections = None
 
@@ -284,7 +306,7 @@ class Settings(RequestHandler):
 
 class Application(tornado.web.Application):
 
-    def __init__(self, master, debug):
+    def __init__(self, master, debug, wauthenticator):
         self.master = master
         handlers = [
             (r"/", IndexHandler),
@@ -308,5 +330,6 @@ class Application(tornado.web.Application):
             xsrf_cookies=True,
             cookie_secret=os.urandom(256),
             debug=debug,
+            wauthenticator=wauthenticator,
         )
         super(Application, self).__init__(handlers, **settings)