You Can't Keep the Change is a 1940 thriller novel by the British writer Peter Cheyney. It is the third in his series of novels featuring the London private detective Slim Callaghan, a British version of the increasingly popular hardboiled American detectives.
Slim Callaghan is called to Margraud Manor in Devon where valuable jewels have been stolen. His investigations take him to a shady nightclub in London haunted by the criminal classes.