Angular2 Cannot find namespace 'google'

I am working with angular2-google-maps and latest version of Angular2. I am trying to convert some of the local map component functions into services in their own file maps.service.ts. For example:

map.component.ts

getGeoLocation(lat: number, lng: number) {
if (navigator.geolocation) {
    let geocoder = new google.maps.Geocoder();
    let latlng = new google.maps.LatLng(lat, lng);
    let request = { latLng: latlng };
    geocoder.geocode(request, (results, status) => {
      if (status == google.maps.GeocoderStatus.OK) {
        let result = results[0];
        if (result != null) {
          this.fillInputs(result.formatted_address);
        } else {
          alert("No address available!");
        }
      }
    });
}
}

Into something like: maps.service.ts

getGeoLocation(lat: number, lng: number): Observable<google.maps.GeocoderResult[]> {
    let geocoder = new google.maps.Geocoder();
    let latlng = new google.maps.LatLng(lat, lng);
    let request = { latLng: latlng };
    return new Observable((observer: Observer<google.maps.GeocoderResult[]>) => {
        geocoder.geocode({ request }, (
            (results: google.maps.GeocoderResult[], status: google.maps.GeocoderStatus) => {
                if (status == google.maps.GeocoderStatus.OK) {
                    observer.next(results);
                    observer.complete();
                } else {
                    console.log('Geocoding service failed due to: ' +status);
                    observer.error(status);
                }
            }
        ));
    });
}

The issue I'm getting is that google variable is not being recognized when I try to use Observer<google.maps.GeocoderResult[]>. I have declare var google: any; outside of the service class as well.

The google variable works in my map.componenet.ts but doesn't get recognized in the maps.service.ts.