The RLM also stipulated that the aircraft should also be able to accept the BMW 801 radial engine in a "Kraftei" (power-egg) unitized installation, with no modification to the engine nacelles. The RLM was not impressed with the new design, as it offered only small improvements over the Ju 88A model in service but suggested that Junkers continue with the prototype work anyway and that they consider fitting the design with the BMW 139 radial. This engine was cancelled only a few weeks later and all designs based on it moved to the newer and more powerful BMW 801.