diff --git a/federationapi/routing/send.go b/federationapi/routing/send.go
index 55899e61d..526480f49 100644
--- a/federationapi/routing/send.go
+++ b/federationapi/routing/send.go
@@ -48,7 +48,7 @@ func Send(
 	}
 
 	var txnEvents struct {
-		Events []json.RawMessage `json:"events"`
+		Events []json.RawMessage `json:"pdus"`
 	}
 
 	if err := json.Unmarshal(request.Content(), &txnEvents); err != nil {
@@ -58,6 +58,7 @@ func Send(
 		}
 	}
 
+	t.PDUs = txnEvents.Events
 	t.Origin = request.Origin()
 	t.TransactionID = txnID
 	t.Destination = cfg.Matrix.ServerName
@@ -84,17 +85,16 @@ type txnReq struct {
 }
 
 func (t *txnReq) processTransaction() (*gomatrixserverlib.RespSend, error) {
-	var pdus []gomatrixserverlib.Event
-
+	var pdus []gomatrixserverlib.HeaderedEvent
 	for _, pdu := range t.PDUs {
 		var header struct {
-			roomID string `json:"room_id"`
+			RoomID string `json:"room_id"`
 		}
 		if err := json.Unmarshal(pdu, &header); err != nil {
 			util.GetLogger(t.context).WithError(err).Warn("Transaction: Failed to extract room ID from event, skipping it.")
 			continue
 		}
-		verReq := api.QueryRoomVersionForRoomRequest{RoomID: header.roomID}
+		verReq := api.QueryRoomVersionForRoomRequest{RoomID: header.RoomID}
 		verRes := api.QueryRoomVersionForRoomResponse{}
 		if err := t.query.QueryRoomVersionForRoom(t.context, &verReq, &verRes); err != nil {
 			util.GetLogger(t.context).WithError(err).Warn("Transaction: Failed to query room version for event, skipping it.")
@@ -105,18 +105,17 @@ func (t *txnReq) processTransaction() (*gomatrixserverlib.RespSend, error) {
 			util.GetLogger(t.context).WithError(err).Warn("Transaction: Failed to parse event JSON, skipping it.")
 			continue
 		}
-		pdus = append(pdus, event)
-	}
-
-	// Check the event signatures
-	if err := gomatrixserverlib.VerifyAllEventSignatures(t.context, pdus, t.keys); err != nil {
-		return nil, err
+		if err := gomatrixserverlib.VerifyAllEventSignatures(t.context, []gomatrixserverlib.Event{event}, t.keys); err != nil {
+			util.GetLogger(t.context).WithError(err).Warnf("Transaction: Couldn't validate signature of event %q, skipping it.", event.EventID())
+			return nil, err
+		}
+		pdus = append(pdus, event.Headered(verRes.RoomVersion))
 	}
 
 	// Process the events.
 	results := map[string]gomatrixserverlib.PDUResult{}
 	for _, e := range pdus {
-		err := t.processEvent(e)
+		err := t.processEvent(e.Event)
 		if err != nil {
 			// If the error is due to the event itself being bad then we skip
 			// it and move onto the next event. We report an error so that the
@@ -187,7 +186,7 @@ func (t *txnReq) processEvent(e gomatrixserverlib.Event) error {
 	}
 
 	if !stateResp.PrevEventsExist {
-		return t.processEventWithMissingState(e)
+		return t.processEventWithMissingState(e, stateResp.RoomVersion)
 	}
 
 	// Check that the event is allowed by the state at the event.
@@ -223,7 +222,7 @@ func checkAllowedByState(e gomatrixserverlib.Event, stateEvents []gomatrixserver
 	return gomatrixserverlib.Allowed(e, &authUsingState)
 }
 
-func (t *txnReq) processEventWithMissingState(e gomatrixserverlib.Event) error {
+func (t *txnReq) processEventWithMissingState(e gomatrixserverlib.Event, roomVersion gomatrixserverlib.RoomVersion) error {
 	// We are missing the previous events for this events.
 	// This means that there is a gap in our view of the history of the
 	// room. There two ways that we can handle such a gap:
@@ -240,7 +239,7 @@ func (t *txnReq) processEventWithMissingState(e gomatrixserverlib.Event) error {
 	// need to fallback to /state.
 	// TODO: Attempt to fill in the gap using /get_missing_events
 	// TODO: Attempt to fetch the state using /state_ids and /events
-	state, err := t.federation.LookupState(t.context, t.Origin, e.RoomID(), e.EventID())
+	state, err := t.federation.LookupState(t.context, t.Origin, e.RoomID(), e.EventID(), roomVersion)
 	if err != nil {
 		return err
 	}
@@ -258,7 +257,7 @@ retryAllowedState:
 				if s.EventID() != missing.AuthEventID {
 					continue
 				}
-				err = t.processEventWithMissingState(s)
+				err = t.processEventWithMissingState(s, roomVersion)
 				// If there was no error retrieving the event from federation then
 				// we assume that it succeeded, so retry the original state check
 				if err == nil {
@@ -270,12 +269,6 @@ retryAllowedState:
 		return err
 	}
 
-	verReq := api.QueryRoomVersionForRoomRequest{RoomID: e.RoomID()}
-	verRes := api.QueryRoomVersionForRoomResponse{}
-	if err := t.query.QueryRoomVersionForRoom(context.Background(), &verReq, &verRes); err != nil {
-		return err
-	}
-
 	// pass the event along with the state to the roomserver
-	return t.producer.SendEventWithState(t.context, state, e.Headered(verRes.RoomVersion))
+	return t.producer.SendEventWithState(t.context, state, e.Headered(roomVersion))
 }