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kotlinlang

I have two types, one a subclass of the other, and I’m trying to make it work with the serialization library:

```
@Serializable
open class Foo(open val foo: String)

@Serializable
data class Bar(override val foo: String, val bar: String) : Foo(foo)
```
The compiler is pointing on `Bar` that I have `foo` declared twice (`has duplicate serial name of property foo, either in it or its parents`). I could not find this scenario on the polymorphism doc. Does anyone know how to get around this?

You can do something like this at the cost of making `Foo` abstract:
```
@Serializable
abstract class Foo {
    abstract val foo : String
}

@Serializable
data class Bar(override val foo: String, val bar: String) : Foo()
```



This is usually acceptable because non-abstract non-interface open classes are frowned upon these days. If you need `Foo` to not be abstract I dont know. Not being able to override concrete vals is probably not intended, and could be grounds for an issue.

Thanks Fudge, that’s a good option, but i need serialization to be able to instantiate `Foo` too. This is a sample of a problem, but the real class has about 12 properties that I’d have to repeat on `Bar`` :confused: