diff --git a/federationapi/routing/send.go b/federationapi/routing/send.go
index 15484dba..518b4bc2 100644
--- a/federationapi/routing/send.go
+++ b/federationapi/routing/send.go
@@ -508,15 +508,6 @@ func (t *txnReq) processEvent(ctx context.Context, e *gomatrixserverlib.Event) e
 		return fmt.Errorf("t.rsAPI.QueryMissingAuthPrevEvents: %w", err)
 	}
 
-	// Prepare a map of all the events we already had before this point, so
-	// that we don't send them to the roomserver again.
-	for _, eventID := range append(e.AuthEventIDs(), e.PrevEventIDs()...) {
-		t.hadEvents[eventID] = true
-	}
-	for _, eventID := range append(stateResp.MissingAuthEventIDs, stateResp.MissingPrevEventIDs...) {
-		t.hadEvents[eventID] = false
-	}
-
 	if !stateResp.RoomExists {
 		// TODO: When synapse receives a message for a room it is not in it
 		// asks the remote server for the state of the room so that it can
@@ -527,6 +518,15 @@ func (t *txnReq) processEvent(ctx context.Context, e *gomatrixserverlib.Event) e
 		return roomNotFoundError{e.RoomID()}
 	}
 
+	// Prepare a map of all the events we already had before this point, so
+	// that we don't send them to the roomserver again.
+	for _, eventID := range append(e.AuthEventIDs(), e.PrevEventIDs()...) {
+		t.hadEvents[eventID] = true
+	}
+	for _, eventID := range append(stateResp.MissingAuthEventIDs, stateResp.MissingPrevEventIDs...) {
+		t.hadEvents[eventID] = false
+	}
+
 	if len(stateResp.MissingAuthEventIDs) > 0 {
 		t.work = MetricsWorkMissingAuthEvents
 		logger.Infof("Event refers to %d unknown auth_events", len(stateResp.MissingAuthEventIDs))
diff --git a/federationapi/routing/send_test.go b/federationapi/routing/send_test.go
index b14cbd35..98ff1a0a 100644
--- a/federationapi/routing/send_test.go
+++ b/federationapi/routing/send_test.go
@@ -370,7 +370,7 @@ func mustCreateTransaction(rsAPI api.RoomserverInternalAPI, fedClient txnFederat
 		keys:       &test.NopJSONVerifier{},
 		federation: fedClient,
 		haveEvents: make(map[string]*gomatrixserverlib.HeaderedEvent),
-		newEvents:  make(map[string]bool),
+		hadEvents:  make(map[string]bool),
 		roomsMu:    internal.NewMutexByRoom(),
 	}
 	t.PDUs = pdus