We examine how a lender of last resort (LLR) and liquidity regulation jointly shape bank fragility when both liquidity and debt pricing are endogenous. In a global-games model of rollover risk, a bank's ex-ante fragility-the probability of a run-depends on how liquidity choices interact with the pricing of short-term debt. We show that LLR policy on its own can backfire: by reducing incentives to self-insure with liquid reserves, it raises debt burdens and amplifies fragility. Minimum liquidity requirements counteract this effect by strengthening balance-sheet resilience and making central-bank support more targeted. Together, the two instruments deliver greater stability and welfare than either in isolation. The analysis highlights a new micro-prudential role for liquidity regulation-enhancing the social value of the LLR.