typescript 3.0和react defaultProps

如果我有这样一个道具定义:

interface Props {
  Layout?: LayoutComponent;
}

如果我在 ClassComponent

class MyComp extends React.Component<Props> {
  static defaultProps: Pick<Props, 'Layout'> = {
    Layout: ({ children }) => <>{children}</>
  };
}

Typescript不接受不能未定义的事实:

render() {
    const { previousLocation, data } = this.state;
    const { location, Layout } = this.props;
    const initialData = this.prefetcherCache[location.pathname] || data;

    return (
      <Layout> // JSX element type 'Layout' does not have any construct or call signatures.
        <Switch>

它永远不应该因为 defaultProps . Typescript不接受这个。

有没有办法让编译器知道它不能是未定义的?