How to register global components with vue-router

I'm using Vue.js with the vue-cli. I chose for the webpack setup. I wired up the main.js file for routing, though I can't find a way to globally register my components.

main.js

import Vue from 'vue'
import VueRouter from 'vue-router'
import App from './App'
import Companies from './components/pages/Companies'
import Income from './components/pages/Income'
import Login from './components/pages/Login'

Vue.use(VueRouter)

let router = new VueRouter()

router.map({
  '/companies': {
    component: Companies
  },
  '/income': {
    component: Income
  },
  'login': {
    component: Login
  }
})

router.start(App, 'body')

App.vue

<template>
  <div>
    <router-view></router-view>
  </div>
</template>
<script>
import {Auth} from './lib/api'
import Loader from './components/Loader'

export default {
  components: {
    Loader
  },
  ready () {
    Auth.isLoggedIn().then(
      (response) => {
        if (response.data === false) {
          this.$router.go('/login')
        } else {
          this.$router.go('/companies')
        }
      },
      (response) => {
        this.$router.go('/login')
      }
    )
  }
}
</script>

When I use my Loader component in some view, I get the following warning.

[Vue warn]: Unknown custom element: - did you register the component correctly? For recursive components, make sure to provide the "name" option.

I provided the name in the component and it didn't make any difference. I'm using the loader-component in the login-view.
I found out that I should either define the component in the component that I'm going to use it or globally. Though, I can't find out how to define it globally with the routing.