diff --git a/shared/relay/client/dialer/quic/quic.go b/shared/relay/client/dialer/quic/quic.go
index 78462837d..2d7b00a80 100644
--- a/shared/relay/client/dialer/quic/quic.go
+++ b/shared/relay/client/dialer/quic/quic.go
@@ -89,12 +89,12 @@ func prepareURL(address string) (string, error) {
 	finalHost, finalPort, err := net.SplitHostPort(host)
 	if err != nil {
 		if strings.Contains(err.Error(), "missing port") {
-			return host + ":" + defaultPort, nil
+			return net.JoinHostPort(strings.Trim(host, "[]"), defaultPort), nil
 		}
 
 		// return any other split error as is
 		return "", err
 	}
 
-	return finalHost + ":" + finalPort, nil
+	return net.JoinHostPort(finalHost, finalPort), nil
 }