A surgical instrument. In one form, the surgical instrument includes a housing that has an interchangeable shaft assembly removably attached thereto. The interchangeable shaft assembly includes an elongate shaft that has a surgical end effector operably coupled thereto for selective articulation relative to the elongate shaft. An articulation system is configured to selectively apply articulation motions to the surgical end effector when the articulation system is in an actuated orientation. A locking arrangement prevents detachment of the interchangeable shaft assembly from the housing when the articulation system is in the actuated orientation.