T. Onoma schrieb: > I've tried it three times. Unless I'm missing something it doesn't fly: > > module Tes > class Object > def t > puts "x" > end > end > end > > include Tes > o = Object.new > o.t > > #=> undefined method `t' for #<Object:0x402a8d7c> (NoMethodError) Hi T., the Object class you define in module Tes isn't the top-level class Object but the new class Tes::Object. So either change the calling code to # include Tes <-- not needed anymore o = Tes::Object.new o.t or don't define a new class in Tes but simply include the module in the top-level class Object: module Tes def t puts "x" end end class Object include Tes end o = Object.new o.t or extend only the new Object instance with the module: module Tes def t puts "x" end end o = Object.new o.extend Tes o.t Regards, Pit