xcode how to refresh MapView with custom annotations?

Question

I am using MapView with Custom Annotations. I let user change map view type and once it is changed then all the annotations are looking as default (red).

Is there anything special I need to do to keep my annotations with custom view? How can I get custom view back?

-(void)changeMapType:(id)sender
{
    switch (((UISegmentedControl *)sender).selectedSegmentIndex) {
        case 0:
            map.mapType = MKMapTypeStandard;
            break;
        case 1:
            map.mapType = MKMapTypeHybrid;
            break;
        case 2:
            map.mapType = MKMapTypeSatellite;
            break;

        default:
            map.mapType = MKMapTypeStandard;
            break;
    }
}