diff --git a/changelog.d/4402.misc b/changelog.d/4402.misc
new file mode 100644
index 0000000000..4a0063ed34
--- /dev/null
+++ b/changelog.d/4402.misc
@@ -0,0 +1 @@
+Implement server support for MSC1794 - Federation v2 Invite API
diff --git a/synapse/api/urls.py b/synapse/api/urls.py
index ba019001ff..8102176653 100644
--- a/synapse/api/urls.py
+++ b/synapse/api/urls.py
@@ -26,6 +26,7 @@ CLIENT_PREFIX = "/_matrix/client/api/v1"
 CLIENT_V2_ALPHA_PREFIX = "/_matrix/client/v2_alpha"
 FEDERATION_PREFIX = "/_matrix/federation"
 FEDERATION_V1_PREFIX = FEDERATION_PREFIX + "/v1"
+FEDERATION_V2_PREFIX = FEDERATION_PREFIX + "/v2"
 STATIC_PREFIX = "/_matrix/static"
 WEB_CLIENT_PREFIX = "/_matrix/client"
 CONTENT_REPO_PREFIX = "/_matrix/content"
diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py
index 98722ae543..37d29e7027 100644
--- a/synapse/federation/federation_server.py
+++ b/synapse/federation/federation_server.py
@@ -369,13 +369,13 @@ class FederationServer(FederationBase):
         })
 
     @defer.inlineCallbacks
-    def on_invite_request(self, origin, content):
+    def on_invite_request(self, origin, content, room_version):
         pdu = event_from_pdu_json(content)
         origin_host, _ = parse_server_name(origin)
         yield self.check_server_matches_acl(origin_host, pdu.room_id)
         ret_pdu = yield self.handler.on_invite_request(origin, pdu)
         time_now = self._clock.time_msec()
-        defer.returnValue((200, {"event": ret_pdu.get_pdu_json(time_now)}))
+        defer.returnValue({"event": ret_pdu.get_pdu_json(time_now)})
 
     @defer.inlineCallbacks
     def on_send_join_request(self, origin, content):
diff --git a/synapse/federation/transport/server.py b/synapse/federation/transport/server.py
index e592269cf4..4557a9e66e 100644
--- a/synapse/federation/transport/server.py
+++ b/synapse/federation/transport/server.py
@@ -21,8 +21,9 @@ import re
 from twisted.internet import defer
 
 import synapse
+from synapse.api.constants import RoomVersions
 from synapse.api.errors import Codes, FederationDeniedError, SynapseError
-from synapse.api.urls import FEDERATION_V1_PREFIX
+from synapse.api.urls import FEDERATION_V1_PREFIX, FEDERATION_V2_PREFIX
 from synapse.http.endpoint import parse_and_validate_server_name
 from synapse.http.server import JsonResource
 from synapse.http.servlet import (
@@ -490,14 +491,46 @@ class FederationSendJoinServlet(BaseFederationServlet):
         defer.returnValue((200, content))
 
 
-class FederationInviteServlet(BaseFederationServlet):
+class FederationV1InviteServlet(BaseFederationServlet):
     PATH = "/invite/(?P<context>[^/]*)/(?P<event_id>[^/]*)"
 
+    @defer.inlineCallbacks
+    def on_PUT(self, origin, content, query, context, event_id):
+        # We don't get a room version, so we have to assume its EITHER v1 or
+        # v2. This is "fine" as the only difference between V1 and V2 is the
+        # state resolution algorithm, and we don't use that for processing
+        # invites
+        content = yield self.handler.on_invite_request(
+            origin, content, room_version=RoomVersions.V1,
+        )
+
+        # V1 federation API is defined to return a content of `[200, {...}]`
+        # due to a historical bug.
+        defer.returnValue((200, (200, content)))
+
+
+class FederationV2InviteServlet(BaseFederationServlet):
+    PATH = "/invite/(?P<context>[^/]*)/(?P<event_id>[^/]*)"
+
+    PREFIX = FEDERATION_V2_PREFIX
+
     @defer.inlineCallbacks
     def on_PUT(self, origin, content, query, context, event_id):
         # TODO(paul): assert that context/event_id parsed from path actually
         #   match those given in content
-        content = yield self.handler.on_invite_request(origin, content)
+
+        room_version = content["room_version"]
+        event = content["event"]
+        invite_room_state = content["invite_room_state"]
+
+        # Synapse expects invite_room_state to be in unsigned, as it is in v1
+        # API
+
+        event.setdefault("unsigned", {})["invite_room_state"] = invite_room_state
+
+        content = yield self.handler.on_invite_request(
+            origin, event, room_version=room_version,
+        )
         defer.returnValue((200, content))
 
 
@@ -1265,7 +1298,8 @@ FEDERATION_SERVLET_CLASSES = (
     FederationEventServlet,
     FederationSendJoinServlet,
     FederationSendLeaveServlet,
-    FederationInviteServlet,
+    FederationV1InviteServlet,
+    FederationV2InviteServlet,
     FederationQueryAuthServlet,
     FederationGetMissingEventsServlet,
     FederationEventAuthServlet,