diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py
index de4b813a1..7ec1d7a88 100644
--- a/synapse/federation/federation_client.py
+++ b/synapse/federation/federation_client.py
@@ -521,7 +521,7 @@ class FederationClient(FederationBase):
         raise RuntimeError("Failed to %s via any server", description)
 
     def make_membership_event(self, destinations, room_id, user_id, membership,
-                              content={},):
+                              content, params):
         """
         Creates an m.room.member event, with context, without participating in the room.
 
@@ -537,8 +537,10 @@ class FederationClient(FederationBase):
             user_id (str): The user whose membership is being evented.
             membership (str): The "membership" property of the event. Must be
                 one of "join" or "leave".
-            content (object): Any additional data to put into the content field
+            content (dict): Any additional data to put into the content field
                 of the event.
+            params (dict[str, str|Iterable[str]]): Query parameters to include in the
+                request.
         Return:
             Deferred: resolves to a tuple of (origin (str), event (object))
             where origin is the remote homeserver which generated the event.
@@ -558,7 +560,7 @@ class FederationClient(FederationBase):
         @defer.inlineCallbacks
         def send_request(destination):
             ret = yield self.transport_layer.make_membership_event(
-                destination, room_id, user_id, membership
+                destination, room_id, user_id, membership, params,
             )
 
             pdu_dict = ret.get("event", None)
diff --git a/synapse/federation/transport/client.py b/synapse/federation/transport/client.py
index 4529d454a..b4fbe2c9d 100644
--- a/synapse/federation/transport/client.py
+++ b/synapse/federation/transport/client.py
@@ -195,7 +195,7 @@ class TransportLayerClient(object):
 
     @defer.inlineCallbacks
     @log_function
-    def make_membership_event(self, destination, room_id, user_id, membership):
+    def make_membership_event(self, destination, room_id, user_id, membership, params):
         """Asks a remote server to build and sign us a membership event
 
         Note that this does not append any events to any graphs.
@@ -205,6 +205,8 @@ class TransportLayerClient(object):
             room_id (str): room to join/leave
             user_id (str): user to be joined/left
             membership (str): one of join/leave
+            params (dict[str, str|Iterable[str]]): Query parameters to include in the
+                request.
 
         Returns:
             Deferred: Succeeds when we get a 2xx HTTP response. The result
@@ -241,6 +243,7 @@ class TransportLayerClient(object):
         content = yield self.client.get_json(
             destination=destination,
             path=path,
+            args=params,
             retry_on_dns_fail=retry_on_dns_fail,
             timeout=20000,
             ignore_backoff=ignore_backoff,
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index 533b82c78..0dffd44e2 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -30,7 +30,12 @@ from unpaddedbase64 import decode_base64
 
 from twisted.internet import defer
 
-from synapse.api.constants import EventTypes, Membership, RejectedReason
+from synapse.api.constants import (
+    KNOWN_ROOM_VERSIONS,
+    EventTypes,
+    Membership,
+    RejectedReason,
+)
 from synapse.api.errors import (
     AuthError,
     CodeMessageException,
@@ -922,6 +927,9 @@ class FederationHandler(BaseHandler):
             joinee,
             "join",
             content,
+            params={
+                "ver": KNOWN_ROOM_VERSIONS,
+            },
         )
 
         # This shouldn't happen, because the RoomMemberHandler has a
@@ -1187,13 +1195,14 @@ class FederationHandler(BaseHandler):
 
     @defer.inlineCallbacks
     def _make_and_verify_event(self, target_hosts, room_id, user_id, membership,
-                               content={},):
+                               content={}, params=None):
         origin, pdu = yield self.federation_client.make_membership_event(
             target_hosts,
             room_id,
             user_id,
             membership,
             content,
+            params=params,
         )
 
         logger.debug("Got response to make_%s: %s", membership, pdu)
diff --git a/synapse/http/matrixfederationclient.py b/synapse/http/matrixfederationclient.py
index bf1aa2950..b3f5415aa 100644
--- a/synapse/http/matrixfederationclient.py
+++ b/synapse/http/matrixfederationclient.py
@@ -439,7 +439,7 @@ class MatrixFederationHttpClient(object):
         defer.returnValue(json.loads(body))
 
     @defer.inlineCallbacks
-    def get_json(self, destination, path, args={}, retry_on_dns_fail=True,
+    def get_json(self, destination, path, args=None, retry_on_dns_fail=True,
                  timeout=None, ignore_backoff=False):
         """ GETs some json from the given host homeserver and path
 
@@ -447,7 +447,7 @@ class MatrixFederationHttpClient(object):
             destination (str): The remote server to send the HTTP request
                 to.
             path (str): The HTTP path.
-            args (dict): A dictionary used to create query strings, defaults to
+            args (dict|None): A dictionary used to create query strings, defaults to
                 None.
             timeout (int): How long to try (in ms) the destination for before
                 giving up. None indicates no timeout and that the request will
@@ -702,6 +702,9 @@ def check_content_type_is_json(headers):
 
 
 def encode_query_args(args):
+    if args is None:
+        return b""
+
     encoded_args = {}
     for k, vs in args.items():
         if isinstance(vs, string_types):