To manage the evolution of software systems effectively, software developers must understand software systems, identify and evaluate alternative modification strategies, implement appropriate modifications, and validate the correctness of the modifications. One analysis technique that assists in many of these activities is program slicing. To facilitate the application of slicing to large software systems, we adapted a control-flow-based interprocedural slicing algorithm so that it accounts for interprocedural control dependencies not recognized by other slicing algorithms, and reuses slicing information for improved efficiency. Our initial studies suggest that additional slice accuracy and slicing efficiency may be achieved with our algorithm.