diff --git a/federationsender/queue/destinationqueue.go b/federationsender/queue/destinationqueue.go
index a574950cd..45faa287c 100644
--- a/federationsender/queue/destinationqueue.go
+++ b/federationsender/queue/destinationqueue.go
@@ -94,8 +94,11 @@ func (oq *destinationQueue) sendInvite(ev *gomatrixserverlib.InviteV2Request) {
 // backgroundSend is the worker goroutine for sending events.
 // nolint:gocyclo
 func (oq *destinationQueue) backgroundSend() {
-	// Mark the worker as running for its lifetime.
-	oq.running.Store(true)
+	// Check if a worker is already running, and if it isn't, then
+	// mark it as started.
+	if !oq.running.CAS(false, true) {
+		return
+	}
 	defer oq.running.Store(false)
 
 	for {
diff --git a/federationsender/queue/queue.go b/federationsender/queue/queue.go
index 35b0bb7f0..aae6c53a0 100644
--- a/federationsender/queue/queue.go
+++ b/federationsender/queue/queue.go
@@ -86,7 +86,7 @@ func (oqs *OutgoingQueues) SendEvent(
 	}
 
 	// Remove our own server from the list of destinations.
-	destinations = filterDestinations(oqs.origin, destinations)
+	destinations = filterAndDedupeDests(oqs.origin, destinations)
 
 	log.WithFields(log.Fields{
 		"destinations": destinations, "event": ev.EventID(),
@@ -145,7 +145,7 @@ func (oqs *OutgoingQueues) SendEDU(
 	}
 
 	// Remove our own server from the list of destinations.
-	destinations = filterDestinations(oqs.origin, destinations)
+	destinations = filterAndDedupeDests(oqs.origin, destinations)
 
 	if len(destinations) > 0 {
 		log.WithFields(log.Fields{
@@ -160,9 +160,9 @@ func (oqs *OutgoingQueues) SendEDU(
 	return nil
 }
 
-// filterDestinations removes our own server from the list of destinations.
-// Otherwise we could end up trying to talk to ourselves.
-func filterDestinations(origin gomatrixserverlib.ServerName, destinations []gomatrixserverlib.ServerName) (
+// filterAndDedupeDests removes our own server from the list of destinations
+// and deduplicates any servers in the list that may appear more than once.
+func filterAndDedupeDests(origin gomatrixserverlib.ServerName, destinations []gomatrixserverlib.ServerName) (
 	result []gomatrixserverlib.ServerName,
 ) {
 	strs := make([]string, len(destinations))
diff --git a/roomserver/internal/input.go b/roomserver/internal/input.go
index a3a88e409..ab3d7516b 100644
--- a/roomserver/internal/input.go
+++ b/roomserver/internal/input.go
@@ -18,7 +18,6 @@ package internal
 import (
 	"context"
 	"encoding/json"
-	"fmt"
 
 	"github.com/Shopify/sarama"
 	"github.com/matrix-org/dendrite/roomserver/api"
@@ -68,7 +67,6 @@ func (r *RoomserverInternalAPI) InputRoomEvents(
 		// loopback room event containing the invite, for local invites.
 		// If it does, we should process it with the room events below.
 		if loopback != nil {
-			fmt.Println("LOOPING BACK", string(loopback.Event.JSON()))
 			request.InputRoomEvents = append(request.InputRoomEvents, *loopback)
 		}
 	}