Why es6 react component works only with “export default”?

This component does work:

export class Template extends React.Component {
    render() {
        return (
            <div> component </div>
        );
    }
};
export default Template;

If i remove last row, it doesn’t work.

Uncaught TypeError: Cannot read property 'toUpperCase' of undefined

I guess, I don’t understand something in es6 syntax. Isn’t it have to export without sign “default”?