Remove ugly DatePicker shadows in Spinner mode

I am trying to include DatePicker in my Activity which looks like this:

but no matter which theme I use, it looks like this: shadows on spinners:

I was unable to find any attributes that affect the shadow color, remove it, or whatever. Is it possible to change this or do I need to write a custom view to have some control over the visuals? (Note: this is not a DatePickerDialog, this is a DatePicker).