Sealed interface not supported

[GrahamBorland]

package ynab.slik.data.repository

import deezer.kustomexport.KustomExport

@KustomExport
sealed interface InvalidDataError

@KustomExport
class InvalidNumber(val number: Int) : InvalidDataError

@KustomExport
class InvalidName(val name: String) : InvalidDataError

This fails to compile:

> Task :lib:compileKotlinJs FAILED
e: file:///Users/graham/Work/YNAB/slik/lib/build/generated/ksp/js/jsMain/kotlin/ynab/slik/data/repository/js/InvalidDataError.kt:11:5 Inheritance of sealed classes or interfaces from different module is prohibited
e: file:///Users/graham/Work/YNAB/slik/lib/build/generated/ksp/js/jsMain/kotlin/ynab/slik/data/repository/js/InvalidDataError.kt:11:5 Inheritor of sealed class or interface declared in package ynab.slik.data.repository.js but it must be in package ynab.slik.data.repository where base class is declared

FAILURE: Build failed with an exception.

If I change the sealed interface to sealed class, then it works.

package ynab.slik.data.repository

import deezer.kustomexport.KustomExport

@KustomExport
sealed class InvalidDataError

@KustomExport
class InvalidNumber(val number: Int) : InvalidDataError()

@KustomExport
class InvalidName(val name: String) : InvalidDataError()

[GrahamBorland]

The generated wrapper for the sealed interface looks like this:

package ynab.slik.`data`.repository.js

import kotlin.js.JsExport
import ynab.slik.`data`.repository.InvalidDataError as CommonInvalidDataError

@JsExport
public external interface InvalidDataError

private class ImportedInvalidDataError(
    internal val exported: InvalidDataError,
) : CommonInvalidDataError

private class ExportedInvalidDataError(
    internal val common: CommonInvalidDataError,
) : InvalidDataError

public fun CommonInvalidDataError.exportInvalidDataError(): InvalidDataError =
        (this as? ImportedInvalidDataError)?.exported ?: ExportedInvalidDataError(this)

public fun InvalidDataError.importInvalidDataError(): CommonInvalidDataError =
        (this as? ExportedInvalidDataError)?.common ?: ImportedInvalidDataError(this)

It doesn't compile because ImportedInvalidDataError is trying to implement CommonInvalidDataError which is the original sealed interface, and it's in a different package (not the .js package).