In a judgment issued on June 6, 2019 (Judgment), the Colombian Constitutional Court (Court) examined the constitutionality of the Agreement for the Reciprocal Promotion and Protection of Investments between Colombia and France (Agreement). The Court upheld the constitutionality of the Agreement on the condition that the government adopt a joint interpretative statement with France to clarify some of its provisions and prevent interpretations contrary to the Colombian constitutional order. In doing so, the Court articulated a standard of review that takes into account the benefits and costs of international investment agreements (IIAs), the application of which entailed an insightful examination of the Agreement in light of the decisions of investment tribunals. The judgment raises significant issues of public international law, including the practical implications of conditioning ratification of the Agreement on adoption of a joint interpretative statement and the role of such statements in the interpretation of IIAs. Furthermore, the judgment makes important contributions to the ongoing process of reform of the investment treaty regime and the strategies adopted by states to counter the adverse impacts of IIAs on regulatory autonomy.