A child play yard includes a frame, a floor coupled to a lower portion of the frame, and a mattress configured to be removably coupled to the floor. The mattress includes a lower side to which is coupled a clip assembly including a base and a leg pivotally coupled to the base. The leg includes a detent extending therefrom. The floor includes a retention assembly having a first aperture through which the leg of the clip assembly passes and a second aperture through which the detent passes when the mattress is coupled to the floor.