Component properties passProps does not pass functions

Wanted to move the state of the tabs example from the Wiki up into the App.js and it does not seem to pass functions in passProps.

App.js

  constructor(props) {
    super(props);
    this.handleTabChange = this.handleTabChange.bind(this)
    this.state = { selectedTab: 'home' }
  }

componentDidMount() {
  const selectedTab = this.state.selectedTab
  Turbolinks.startSingleScreenApp({ 
    component: 'TabbedView',
    hidesNavBar: true,
    passProps: {
       selectedTab: selectedTab,
       onTabChange: this.handleTabChange
     } 
   })
}

  handleTabChange = (tab) => {
    this.setState({ selectedTab: tab });
  }

When checking the react debugger output onTabChange is never there.

Running "TabbedView" with {"rootTag":181,"initialProps":{"selectedTab":"home"}}

TabbedView.js

  handleChange = (tab) => {
    this.props.onTabChange(tab)
  }

The above fails with