In a move that Chairman Jerome Powell called a “robust updating” of Fed policy, the central bank formally agreed to a policy of “average inflation targeting.” That means it will allow inflation to run “moderately” above the Fed’s 2% goal “for some time” following periods when it has run below that objective.

The changes were codified in a policy blueprint called the Statement on Longer-Run Goals and Monetary Policy Strategy, first adopted in 2012, that has informed the Fed’s approach to interest rates and general economic growth.

As a practical matter, the move means the Fed will be less inclined to hike interest rates when the unemployment rate falls, so long as inflation does not creep up as well. Central bank officials traditionally have believed that low unemployment leads to dangerously higher levels of inflation, and they’ve moved preemptively to head it off.