diff --git a/synapse/api/constants.py b/synapse/api/constants.py
index 05fc84f6e..592abd844 100644
--- a/synapse/api/constants.py
+++ b/synapse/api/constants.py
@@ -34,7 +34,7 @@ class Membership:
 
     INVITE = "invite"
     JOIN = "join"
-    KNOCK = "xyz.amorgan.knock"
+    KNOCK = "knock"
     LEAVE = "leave"
     BAN = "ban"
     LIST = (INVITE, JOIN, KNOCK, LEAVE, BAN)
@@ -50,7 +50,7 @@ class PresenceState:
 
 class JoinRules:
     PUBLIC = "public"
-    KNOCK = "xyz.amorgan.knock"
+    KNOCK = "knock"
     INVITE = "invite"
     PRIVATE = "private"
 
diff --git a/tests/rest/client/v2_alpha/test_sync.py b/tests/rest/client/v2_alpha/test_sync.py
index 8481654ae..f4438e163 100644
--- a/tests/rest/client/v2_alpha/test_sync.py
+++ b/tests/rest/client/v2_alpha/test_sync.py
@@ -16,7 +16,12 @@
 import json
 
 import synapse.rest.admin
-from synapse.api.constants import EventContentFields, EventTypes, RelationTypes
+from synapse.api.constants import (
+    EventContentFields,
+    EventTypes,
+    Membership,
+    RelationTypes,
+)
 from synapse.api.room_versions import RoomVersions
 from synapse.rest.client.v1 import login, room
 from synapse.rest.client.v2_alpha import knock, read_marker, sync
@@ -379,7 +384,7 @@ def test_knock_room_state(self):
 
         # We expect to see the knock event in the stripped room state later
         self.expected_room_state[EventTypes.Member] = {
-            "content": {"membership": "xyz.amorgan.knock", "displayname": "knocker"},
+            "content": {"membership": Membership.KNOCK, "displayname": "knocker"},
             "state_key": "@knocker:test",
         }
 
@@ -390,7 +395,7 @@ def test_knock_room_state(self):
         self.assertEqual(channel.code, 200, channel.json_body)
 
         # Extract the stripped room state events from /sync
-        knock_entry = channel.json_body["rooms"]["xyz.amorgan.knock"]
+        knock_entry = channel.json_body["rooms"][Membership.KNOCK]
         room_state_events = knock_entry[self.room_id]["knock_state"]["events"]
 
         # Validate that the knock membership event came last