How do I configure devise to use a custom email layout?

When I say layout I don't mean just simply the views, I generate those. On all my own mailers I'm using a default layout. Which I define in the SomeMailer.rb file

#some_mailer.rb
class SomeMailer < ActionMailer::Base
  layout 'sometemplate'

Is there some way I can do this for the Devise Mailer et al.?