modifying an association during inheritance

I have a Team class that inherits from a Group class. Both Team and
Groups have memberships through the same association. However, I need
to run a method after a Team memberships is added but not a Group. I
currently have something like this:

class Group < ActiveRecord::Base
  has_many :memberships,
           :class_name => 'Connection',
           :foreign_key => 'connectable_id',
           :as => :connectable,
           :dependent => :destroy
end

class Team < Group
  has_many :memberships,
           :class_name => 'Connection',
           :foreign_key => 'connectable_id',
           :as => :connectable,
           :dependent => :destroy,
           :after_add => :add_company_membership

private
   def membership_check(membership)
   end
end

Is there some way to modify the inherited association in Team so that
I don't have to redefine the entire thing but rather just add
the :after_add hook it?

Any help would be appreciated.