diff --git a/clientapi/routing/joinroom.go b/clientapi/routing/joinroom.go
index bf8e978e1..e3748731e 100644
--- a/clientapi/routing/joinroom.go
+++ b/clientapi/routing/joinroom.go
@@ -375,38 +375,8 @@ func (r joinRoomReq) joinRoomUsingServer(roomID string, server gomatrixserverlib
 		return nil, fmt.Errorf("r.federation.SendJoin: %w", err)
 	}
 
-	// A list of events that we have retried, if they were not included in
-	// the auth events supplied in the send_join.
-	retries := map[string]bool{}
-
-retryCheck:
-	if err = respSendJoin.Check(r.req.Context(), r.keyRing, event); err != nil {
-		switch e := err.(type) {
-		case gomatrixserverlib.MissingAuthEventError:
-			// Check that we haven't already retried for this event, prevents
-			// us from ending up in endless loops
-			if _, ok := retries[e.AuthEventID]; !ok {
-				// Ask the server that we're talking to right now for the event
-				tx, txerr := r.federation.GetEvent(r.req.Context(), server, e.AuthEventID)
-				if txerr != nil {
-					return nil, fmt.Errorf("r.federation.GetEvent: %w", txerr)
-				}
-				// For each event returned, add it to the auth events.
-				for _, pdu := range tx.PDUs {
-					ev, everr := gomatrixserverlib.NewEventFromUntrustedJSON(pdu, respMakeJoin.RoomVersion)
-					if everr != nil {
-						return nil, fmt.Errorf("gomatrixserverlib.NewEventFromUntrustedJSON: %w", everr)
-					}
-					respSendJoin.AuthEvents = append(respSendJoin.AuthEvents, ev)
-				}
-				// Mark the event as retried and then give the check another go.
-				retries[e.AuthEventID] = true
-				goto retryCheck
-			}
-			return nil, fmt.Errorf("respSendJoin (after retries): %w", e)
-		default:
-			return nil, fmt.Errorf("respSendJoin: %w", err)
-		}
+	if err = r.checkSendJoinResponse(event, server, respMakeJoin, respSendJoin); err != nil {
+		return nil, err
 	}
 
 	util.GetLogger(r.req.Context()).WithFields(logrus.Fields{
@@ -425,7 +395,7 @@ retryCheck:
 	go func() {
 		ctx := context.Background()
 		if err = r.producer.SendEventWithState(
-			ctx, //r.req.Context(),
+			ctx,
 			gomatrixserverlib.RespState(respSendJoin.RespState),
 			event.Headered(respMakeJoin.RoomVersion),
 		); err != nil {
@@ -441,3 +411,47 @@ retryCheck:
 		}{roomID},
 	}, nil
 }
+
+// checkSendJoinResponse checks that all of the signatures are correct
+// and that the join is allowed by the supplied state.
+func (r joinRoomReq) checkSendJoinResponse(
+	event gomatrixserverlib.Event,
+	server gomatrixserverlib.ServerName,
+	respMakeJoin gomatrixserverlib.RespMakeJoin,
+	respSendJoin gomatrixserverlib.RespSendJoin,
+) error {
+	// A list of events that we have retried, if they were not included in
+	// the auth events supplied in the send_join.
+	retries := map[string]bool{}
+
+retryCheck:
+	if err := respSendJoin.Check(r.req.Context(), r.keyRing, event); err != nil {
+		switch e := err.(type) {
+		case gomatrixserverlib.MissingAuthEventError:
+			// Check that we haven't already retried for this event, prevents
+			// us from ending up in endless loops
+			if _, ok := retries[e.AuthEventID]; !ok {
+				// Ask the server that we're talking to right now for the event
+				tx, txerr := r.federation.GetEvent(r.req.Context(), server, e.AuthEventID)
+				if txerr != nil {
+					return fmt.Errorf("r.federation.GetEvent: %w", txerr)
+				}
+				// For each event returned, add it to the auth events.
+				for _, pdu := range tx.PDUs {
+					ev, everr := gomatrixserverlib.NewEventFromUntrustedJSON(pdu, respMakeJoin.RoomVersion)
+					if everr != nil {
+						return fmt.Errorf("gomatrixserverlib.NewEventFromUntrustedJSON: %w", everr)
+					}
+					respSendJoin.AuthEvents = append(respSendJoin.AuthEvents, ev)
+				}
+				// Mark the event as retried and then give the check another go.
+				retries[e.AuthEventID] = true
+				goto retryCheck
+			}
+			return fmt.Errorf("respSendJoin (after retries): %w", e)
+		default:
+			return fmt.Errorf("respSendJoin: %w", err)
+		}
+	}
+	return nil
+}