A removable, functional module for a wind turbine is provided. The functional module includes a fastening element configured to detachably fasten the functional module to the wind turbine in a predetermined position, wherein the functional module is removable from the predetermined position, when the fastening element is unfastened. The functional module further includes a cover configured to form part of a housing of the wind turbine, when the functional module is in the predetermined position. The functional module is configured to carry out a function contributing to the operation of the wind turbine, when the functional module is in the predetermined position. Furthermore, a corresponding method for coupling a functional module to a wind turbine is also provided.