Default value for decimal scalar in codegen

[cps-cfl]

I've got a schema that boils down to this

scalar Decimal
input MyInput {
  order: Decimal! = 1
}

In my codegen config I've done typeMapping["Decimal"] = "java.math.BigDecimal".

It spits out something like this public val order: BigDecimal = 1, in kotlin and private BigDecimal order = 1; in java neither of which compile.

Is there some trick to making this work or am I missing something?