This paper models monetary policy's transmission to bank risk in presence of a capital requirement ratio. We show that the impact of a change in monetary policy rate on bank's risk level is not independent from the strength of the capital requirement ratio. A monetary easing, as well as a monetary contraction, may lead bank to take more risk according to some effects related to the risk sensitivity of its intermediation margin and risk sensitivity of the prudential tool. We show that the combination of monetary policy with prudential policy has different outcomes in terms of financial stability and expected cost of bank failure.