Conventional wisdom holds that a central bank should tighten monetary policy after a surprise decline in labor supply to offset the inflationary effects of the decline. However, this policy prescription comes from models of monetary policy that abstract from labor force participation. We examine the policy implications of worker entry into and exit from the labor force. We find that cyclical changes in labor force participation call for a less restrictive policy response to a decline in labor supply. The less restrictive policy response is appropriate because policy tightening reduces the labor force and thus raises wage growth. The optimal policy response dampens the reduction in the labor force and brings about a period of higher inflation.