Incorrect approximation for decimal numbers

[journpy]

I expected num2words(98_746_251_323_029.99) to return 'ninety-eight trillion, seven hundred and forty-six billion, two hundred and fifty-one million, three hundred and twenty-three thousand and twenty-nine point nine nine'

but it returns 'ninety-eight trillion, seven hundred and forty-six billion, two hundred and fifty-one million, three hundred and twenty-three thousand and twenty-nine point nine eight'

I tried using the decimal module instead of float num2words(Decimal(98_746_251_323_029.99)) but it returned the same result 'ninety-eight trillion, seven hundred and forty-six billion, two hundred and fifty-one million, three hundred and twenty-three thousand and twenty-nine point nine eight'

Is this an approximation with the library? How do I get correct approximation for decimal values like this?