The regulation of bank liquidity can create a commitment device on repaying depositors in bad states, if deposit insurance is absent. A theoretical model shows that liquidity regulation can: 1) stimulate a deposit inflow, moderating the limited liability inefficiency; 2) promote lending and branching, if deposit growth exceeds the intermediation margin decline. Our empirical test exploits an unexpected policy change, which fostered the liquid assets of Ethiopian banks by 25\% in 2011. Exploiting the cross-sectional heterogeneity in bank size and bank-level databases, we find an increase in deposits, loans and branches, with no decline in profits.