diff --git a/tests/test_terms_auth.py b/tests/test_terms_auth.py
index 5ec5d2b358fd..a3f98a141252 100644
--- a/tests/test_terms_auth.py
+++ b/tests/test_terms_auth.py
@@ -53,7 +53,8 @@ def prepare(self, reactor, clock, hs):
 
     def test_ui_auth(self):
         # Do a UI auth request
-        request, channel = self.make_request(b"POST", self.url, b"{}")
+        request_data = json.dumps({"username": "kermit", "password": "monkey"})
+        request, channel = self.make_request(b"POST", self.url, request_data)
         self.render(request)
 
         self.assertEquals(channel.result["code"], b"401", channel.result)