Criticism of the effects of the international investment regime on state regulatory space (SRS) is on the rise, much of it focusing on the impact of binding arbitration. Specifically, the investor-state dispute settlement (ISDS) provisions found in most bilateral investment treaties (BITs) and other investment agreements have a profound effect on the balance between investor rights and state regulatory space (SRS), raising a debate on their legitimacy. We explore how states perceive the legitimacy of ISDS provisions in light of their experiences with the investment regime through the lens of BIT renegotiation and termination. Renegotiation provides an empirical window for understanding how dissatisfaction with BITs translates into concrete decisions by governments to recalibrate their treaty obligations, perhaps rendering them more legitimate. Based on an original data set comprised of 161 renegotiated agreements, we find that states have not made a systematic effort over the years to recalibrate their BITs for the purpose of preserving more regulatory space. In fact, most renegotiations either leave ISDS provisions unchanged or render them more investor-friendly. However, recent renegotiations show a greater tendency to limit investor protections in ISDS provisions.