Why is this Typescript export undefined?

I am trying to make a NPM package using Typescript and React. (TSX)

I am following this blog post, but trying to make multiple components instead of just one.

When I try and import my module like this

import { HelloWorld } from 'tsx_lib'

It shows up as undefined

console.log(HelloWorld) //undefined

My folder structure looks like this

src /
   GoodbyeWorld.tsx
   HelloWorld.tsx
   index.ts
index.d.ts

Here are the files

GoodbyeWorld.tsx

import * as React from 'react';
import { GoodbyeWorldProps } from '../index';

export default class GoodbyeWorld extends React.Component<any, any> {
  render() {
    return <div style={{ color: this.props.color }}>Goodbye world!</div>;
  }
}

HelloWorld.tsx

import * as React from 'react';
import { HelloWorldProps } from '../index';

export default class HelloWorld extends React.Component<any, any> {
  render() {
    return <div style={{ color: this.props.color }}>Hello world!</div>;
  }
}

index.ts

export * from './HelloWorld';
export * from './GoodbyeWorld';

index.d.ts

import * as React from 'react';

export interface HelloWorldProps extends React.Props<HelloWorld> {
  color: string;
}

export interface GoodbyeWorldProps extends React.Props<HelloWorld> {
  color: string;
}

declare module 'hello-world' {

}

declare module 'goodbye-world' {

}

export class HelloWorld extends React.Component<HelloWorldProps, any> {}
export class GoodbyeWorld extends React.Component<HelloWorldProps, any> {}

What am I doing wrong?