Significance In many marine ecosystems, fisheries target predatory fish, known as piscivores, as well as their prey fish, known as forage fish. It is generally thought that harvesting of forage fish negatively affects piscivore population abundance and resilience. Here, we show that, contrary to this widely held belief, piscivorous fish stocks exposed to high fishing mortality benefit from harvesting of their forage fish. On the other hand, piscivorous fish stocks exposed to low fishing mortality are reduced by harvesting of their forage fish. The beneficial effect occurs when the harvesting of forage fish releases density dependence in the forage-fish population. Our findings have implications for policy advice regarding the management of forage-fish fisheries and the protection of piscivorous fish stocks.