onEnter prop triggers on all components

I am looking for help with my react router onEnter prop. Seems like that onEnter prop is triggered on every component in my app, event though I am not specifying that. Pretty sure it is something related with my router setup.

My code:

<Provider store={store}>
<Router history={browserHistory}>
  <Route path="/" component={App}>
    <Route
      path="/1"
      components={{ main: Hierarchy, sidebar: NavBar }}
      onEnter={AWSApi.tokenIsValid(authHeader)}
    />
    <Route
      path="/2"
      components={{ main: Entities, sidebar: NavBar }}
      onEnter={AWSApi.tokenIsValid(authHeader)}
    />
    <Route
      path="/2/:id"
      component={Analysis}
      onEnter={AWSApi.tokenIsValid(authHeader)}
    />
    <Route path="/1/:id" component={Entity} onEnter={AWSApi.tokenIsValid(authHeader)} />
  </Route>
  <Route path="/login" component={AuthForm} />
  <Route path="/new-password" component={ChangePasswordForm} />
</Router>