diff --git a/federationapi/routing/send.go b/federationapi/routing/send.go
index 6971d5bae..dca6a7ef3 100644
--- a/federationapi/routing/send.go
+++ b/federationapi/routing/send.go
@@ -260,6 +260,7 @@ func (t *txnReq) processTransaction(ctx context.Context) (*gomatrixserverlib.Res
 	for _, e := range pdus {
 		perRoom[e.RoomID()] <- e.Unwrap()
 	}
+	pdus = nil // nolint:ineffassign
 
 	var wg sync.WaitGroup
 	wg.Add(len(perRoom))