How can I stop D from dropping decimals in strings

[Tim via Digitalmars-d-learn]

Hi all,
I have to serialize an array like [0.0, 0.0, 0.0] to a Json 
object. During this process, the serializer creates a string of 
the array, but it creates "[0, 0, 0]", dropping the decimal. How 
can I stop this?