storybook: addon withInfo propTablesExclude does not exclude

Bug or support request summary

I am trying to exclude components from being shown in Prop Tables section like mentioned herer: docs https://github.com/storybooks/storybook/tree/master/addons/info#options-and-defaults

{
/**
   * Exclude Components from being shown in Prop Tables section
   * Accepts an array of component classes or functions
   * @default []
   */
  propTablesExclude: Array<React.ComponentType>,
}

However it does not seem to work and I am getting Prop Tables even for excluded components.

Steps to reproduce

Here is small sample code to test propTablesExclude:

// @flow
import React from 'react';
import { storiesOf } from '@storybook/react';
import { withInfo } from '@storybook/addon-info';

/* eslint-disable react/no-unused-prop-types,react/require-default-props */
type PropsType = {
  label: string,
  onClick?: Function,
  disabled?: boolean,
};

const Button = ({ label, onClick, disabled }: PropsType) => (
  <button onClick={onClick} disabled={disabled}>
    {label}
  </button>
);

Button.defaultProps = {
  disabled: false,
  onClick: () => {},
};

storiesOf('Test', module).add(
  'Exclude component from prop tables',
  withInfo({
    text: 'This can exclude extraneous components from being displayed in prop tables.',
    propTablesExclude: [Button],
  })(() => (
    <div>
      <Button label="Button" />
    </div>
  ))
);

Here is screenshot of Prop Tables for Button being not excluded:

Please specify which version of Storybook and optionally any affected addons that you’re running

    "@storybook/addon-info": "4.0.0-alpha.9",
    "@storybook/react": "4.0.0-alpha.9",

Where to start

My humble guess is that something goes wrong somewhere here: https://github.com/storybooks/storybook/blob/master/addons/info/src/components/Story.js#L314-L324

if (
  typeof children === 'string' ||
  typeof children.type === 'string' ||
  (Array.isArray(this.props.propTablesExclude) && // also ignore excluded types
    ~this.props.propTablesExclude.indexOf(children.type)) // eslint-disable-line no-bitwise
) {
  return;
}
if (children.type && !types.has(children.type)) {
  types.set(children.type, true);
}

When I have changed this code a bit into something like this:

if (
  typeof children === 'string' ||
  typeof children.type === 'string' ||
  ~this.props.propTablesExclude.toString().indexOf(children.type) // eslint-disable-line no-bitwise
) {
  return;
} else if (!types.has(children.type)) {
  types.set(children.type, true);
}

it seemed to fix the issue. But I am not sure if this is the correct/safe way. It would be cool if someone could investigate this.

Thanks