Schema pick help

export class StatusPage extends Schema.Class<StatusPage>('StatusPage')({
    id                : S.String.pipe(Schema.nonEmptyString()),
    description       : S.optionalWith(S.String.pipe(Schema.nonEmptyString()), { exact: true, nullable: true }),
    ...
}) {

}

export const SelectStatusPageSchema = Schema.Struct(StatusPage.fields).pick(
    'description',
  ...
);

{   id: string;   description: string | null; ... }
is not assignable to parameter of type
{   readonly id: string;   readonly description?: string; ...}
Types of property description are incompatible.
Type string | null is not assignable to type string
Type null is not assignable to type string