Fehler kompilieren Typoskript mit Vue.js TS2352

Dies ist mein window.ts

import Vue from 'vue'

interface BrowserWindow extends Window {
  app: Vue
}

const browserWindow = window as BrowserWindow
export default browserWindow

Ich bekomme immer diesen Fehler beim kompilieren

TS2352: Conversion of type 'Window & typeof globalThis' to type 'BrowserWindow' may 
be a mistake because neither type sufficiently overlaps with the other. If this was intentional, 
convert the expression to 'unknown' first.
  Property 'app' is missing in type 'Window & typeof globalThis' but required in type 'BrowserWindow'.