A joint locking device for a convertible roof system is provided. In another aspect of the present invention, an outfolding convertible roof employs a device for deterring member-to-member movement when fully raised. A further aspect of the present invention employs a linearly moving lock for a convertible roof joint, which may be automatically actuated and/or manually actuated. Still another aspect of the present invention provides a joint lock at the A-joint, B-joint, C-joint and/or another joint of the convertible roof top stack mechanism.