Two simple constraints on the item parameters in a response--time model are proposed to control the speededness of an adaptive test. As the constraints are additive, they can easily be included in the constraint set for a shadow-test approach (STA) to adaptive testing. Alternatively, a simple heuristic is presented to control speededness in plain adaptive testing without any constraints. Both types of control are easy to implement and do not require any other real-time parameter estimation during the test than the regular update of the test taker's ability estimate. Evaluation of the two approaches using simulated adaptive testing showed that the STA was especially effective. It guaranteed testing times that differed less than 10 seconds from a reference test across a variety of conditions. (Contains 4 figures and 3 tables.)