diff --git a/udp/conn.go b/udp/conn.go
index 1a275d19..30d89dec 100644
--- a/udp/conn.go
+++ b/udp/conn.go
@@ -31,8 +31,8 @@ func (NoopConn) Rebind() error {
 func (NoopConn) LocalAddr() (netip.AddrPort, error) {
 	return netip.AddrPort{}, nil
 }
-func (NoopConn) ListenOut(_ EncReader) {
-	return
+func (NoopConn) ListenOut(_ EncReader) error {
+	return nil
 }
 func (NoopConn) SupportsMultipleReaders() bool {
 	return false