Set layer definition on overview map

As the subjet says: Is it possible to set a layerdefinition on layers in the overview map?

My map has one service with ID=0, the overviewmap has a service with ID=1. When I try to run a Set Layer Definition with mapservice=1 and layerid=0, I get a message: 'Set Layer Definition: unable to find map service with ID '1' or map service type does not support layer definitions.'

I'm pretty sure that the map service supports layer definitions, so I guess this is not possible, or is it?