Nov. 21 (Bloomberg) — Illinois will have to find a new way to fix the worst pension shortfall in the country after a judge struck down a 2013 law that included raising the retirement age as unconstitutional.

Today's decision by state court Judge John Belz in Springfield undoes a signature achievement of outgoing Democratic Governor Pat Quinn and hands responsibility for finding a solution to the state's $111 billion pension deficit to Republican businessman Bruce Rauner, who defeated him in the Nov. 4 election.

State constitutions have been invoked elsewhere to prevent cuts to public pensions. In Rhode Island, unions settled with the state over pension cuts before their constitutional challenge could be put to the test. In bankruptcy cases in Detroit and California, judges ruled that federal law overrode state bans on cutting pensions.