def add_rnn_decoder_arguments(group):
    """Define arguments for RNN decoder."""
    group.add_argument(
        "--dec-embed-dim",
        default=320,
        type=int,
        help="Number of decoder embeddings dimensions",
    )
    group.add_argument(
        "--dlayers", default=1, type=int, help="Number of decoder layers"
    )
    group.add_argument(
        "--dunits", default=320, type=int, help="Number of decoder hidden units"
    )

    return group