V4 InfiniteScroll event type definition

InifiniteScroll in v4 works fine

I have implement it following the example https://beta.ionicframework.com/docs/api/infinite-scroll

Now, I like to define a type for everything, in the documentation event hasn’t a defined type respectively

loadData(event) {
  setTimeout(function() {
  }, 2000);


I guess event is a CutomEvent

loadData(event: CutomEvent) {

which works fine to recognize target but giving a typing error (on prod build) for complete()

Property `target` doesn't exist does not exist on type `EventTarget`

Do you know which type definition I should/could use?

I’ve open a feature request: https://github.com/ionic-team/ionic/issues/15049