The FAA is looking to develop streamlined launch and reentry licensing requirements for the evolving commercial space industry. A central goal is to move from prescriptive requirements to performance requirements. By focusing on outcomes, performance standards give to developers flexibility and make it possible to find lowest-cost means to achieve compliance. Performance standards can generally accommodate technological change and the emergence of new technology driven hazards in ways that prescriptive standards cannot. However, how performance standards are designed and how they are implemented and enforced matters greatly. This paper uses the case of the Boeing B-737 MAX MCAS certification to illustrate the following mistakes to be avoided when using performance-based safety requirements: excessive trust on quantitative performance requirements, inadequate risk-based design process, and lack of independent design verification by experts.