EF adaptor: any way to set aperture?

I received my NEX adaptor today so I can use my Canon lenses on my NEX6. Works fine, except there's no way to set aperture. I was aware that AF would not work, but is there any way around preventing my Canon lenses to always go wide open (seems to work this way) when using my NEX. I dont mind missing the aperture info in the EXIF data or having to set it manually. I fear it's simply not possible but maybe there's a workaround?