React Router with React 16.6 Suspense "Invalid prop `component` of type `object` supplied to `Route`, expected `function`."

I'm using the latest version (16.6) of React with react-router (4.3.1) and trying to use code splitting using React.Suspense.

Although my routing is working and the code did split into several bundles loaded dynamically, I'm getting a warning about not returning a function, but an object to Route. My code:

import React, { lazy, Suspense } from 'react';
import { Switch, Route, withRouter } from 'react-router-dom';

import Loading from 'common/Loading';

const Prime = lazy(() => import('modules/Prime'));
const Demo = lazy(() => import('modules/Demo'));

const App = () => (
  <Suspense fallback={<Loading>Loading...</Loading>}>
    <Switch>
      <Route path="/" component={Prime} exact />
      <Route path="/demo" component={Demo} />
    </Switch>
  </Suspense>
);

export default withRouter(App);

The console warning is as follows: Warning: Failed prop type: Invalid prop `component` of type `object` supplied to `Route`, expected `function`.

A normal import would return a function, but the dynamic import with lazy() is returning an object.

Any fixes for this?