diff --git a/synapse/rest/client/v1/room.py b/synapse/rest/client/v1/room.py
index 64f51406fb0b..bffd43de5fd2 100644
--- a/synapse/rest/client/v1/room.py
+++ b/synapse/rest/client/v1/room.py
@@ -189,12 +189,6 @@ async def on_PUT(self, request, room_id, event_type, state_key, txn_id=None):
 
         content = parse_json_object_from_request(request)
 
-        if event_type == EventTypes.Aliases:
-            # MSC2260
-            raise SynapseError(
-                400, "Cannot send m.room.aliases events via /rooms/{room_id}/state"
-            )
-
         event_dict = {
             "type": event_type,
             "content": content,
@@ -242,12 +236,6 @@ async def on_POST(self, request, room_id, event_type, txn_id=None):
         requester = await self.auth.get_user_by_req(request, allow_guest=True)
         content = parse_json_object_from_request(request)
 
-        if event_type == EventTypes.Aliases:
-            # MSC2260
-            raise SynapseError(
-                400, "Cannot send m.room.aliases events via /rooms/{room_id}/send"
-            )
-
         event_dict = {
             "type": event_type,
             "content": content,
diff --git a/tests/rest/admin/test_admin.py b/tests/rest/admin/test_admin.py
index e5984aaad851..0342aed416b0 100644
--- a/tests/rest/admin/test_admin.py
+++ b/tests/rest/admin/test_admin.py
@@ -868,6 +868,13 @@ def test_correct_room_attributes(self):
         self.assertEqual(200, int(channel.result["code"]), msg=channel.result["body"])
 
         # Set this new alias as the canonical alias for this room
+        self.helper.send_state(
+            room_id,
+            "m.room.aliases",
+            {"aliases": [test_alias]},
+            tok=self.admin_user_tok,
+            state_key="test",
+        )
         self.helper.send_state(
             room_id,
             "m.room.canonical_alias",
diff --git a/tests/rest/client/v1/test_directory.py b/tests/rest/client/v1/test_directory.py
index 914cf5492716..633b7dbda093 100644
--- a/tests/rest/client/v1/test_directory.py
+++ b/tests/rest/client/v1/test_directory.py
@@ -51,30 +51,26 @@ def prepare(self, reactor, clock, homeserver):
         self.user = self.register_user("user", "test")
         self.user_tok = self.login("user", "test")
 
-    def test_cannot_set_alias_via_state_event(self):
-        self.ensure_user_joined_room()
-        url = "/_matrix/client/r0/rooms/%s/state/m.room.aliases/%s" % (
-            self.room_id,
-            self.hs.hostname,
-        )
-
-        data = {"aliases": [self.random_alias(5)]}
-        request_data = json.dumps(data)
-
-        request, channel = self.make_request(
-            "PUT", url, request_data, access_token=self.user_tok
-        )
-        self.render(request)
-        self.assertEqual(channel.code, 400, channel.result)
+    def test_state_event_not_in_room(self):
+        self.ensure_user_left_room()
+        self.set_alias_via_state_event(403)
 
     def test_directory_endpoint_not_in_room(self):
         self.ensure_user_left_room()
         self.set_alias_via_directory(403)
 
+    def test_state_event_in_room_too_long(self):
+        self.ensure_user_joined_room()
+        self.set_alias_via_state_event(400, alias_length=256)
+
     def test_directory_in_room_too_long(self):
         self.ensure_user_joined_room()
         self.set_alias_via_directory(400, alias_length=256)
 
+    def test_state_event_in_room(self):
+        self.ensure_user_joined_room()
+        self.set_alias_via_state_event(200)
+
     def test_directory_in_room(self):
         self.ensure_user_joined_room()
         self.set_alias_via_directory(200)
@@ -106,6 +102,21 @@ def test_room_creation(self):
         self.render(request)
         self.assertEqual(channel.code, 200, channel.result)
 
+    def set_alias_via_state_event(self, expected_code, alias_length=5):
+        url = "/_matrix/client/r0/rooms/%s/state/m.room.aliases/%s" % (
+            self.room_id,
+            self.hs.hostname,
+        )
+
+        data = {"aliases": [self.random_alias(alias_length)]}
+        request_data = json.dumps(data)
+
+        request, channel = self.make_request(
+            "PUT", url, request_data, access_token=self.user_tok
+        )
+        self.render(request)
+        self.assertEqual(channel.code, expected_code, channel.result)
+
     def set_alias_via_directory(self, expected_code, alias_length=5):
         url = "/_matrix/client/r0/directory/room/%s" % self.random_alias(alias_length)
         data = {"room_id": self.room_id}