We consider how the behaviour of a semiconductor laser subject to phase-conjugate feedback depends on the interaction time of the phase-conjugating mirror. We employ continuation techniques to show how the bifurcation diagram in the plane of feedback strength versus pump current changes as the interaction time of the mirror is increased. This shows that for interaction times below 0.1 ns the assumption of instantaneous feedback is justified. On the other hand, we show that increasingly larger interaction times lead to considerable changes in the size and qualitative structure of the locking region. Our study provides a more global view of the suppression of complicated and chaotic dynamics. © 2003 Elsevier B.V. All rights reserved.