diff --git a/mitmproxy/tools/web/app.py b/mitmproxy/tools/web/app.py
index ad8e5d2a1..8b4a39b6f 100644
--- a/mitmproxy/tools/web/app.py
+++ b/mitmproxy/tools/web/app.py
@@ -451,7 +451,6 @@ class Options(RequestHandler):
             raise APIError(400, "{}".format(err))
 
 
-
 class Application(tornado.web.Application):
     def __init__(self, master, debug):
         self.master = master
diff --git a/test/mitmproxy/tools/web/test_app.py b/test/mitmproxy/tools/web/test_app.py
index d47b1af05..401f9fe65 100644
--- a/test/mitmproxy/tools/web/test_app.py
+++ b/test/mitmproxy/tools/web/test_app.py
@@ -258,6 +258,10 @@ class TestApp(tornado.testing.AsyncHTTPTestCase):
         assert type(j) == list
         assert type(j[0]) == dict
 
+    def test_option_update(self):
+        assert self.put_json("/options", {"anticache": True}).code == 200
+        assert self.put_json("/options", {"wtf": True}).code == 400
+
     def test_err(self):
         with mock.patch("mitmproxy.tools.web.app.IndexHandler.get") as f:
             f.side_effect = RuntimeError