Illinois children must ride in rear-facing child-restraint seats in automobiles until age 2 under a law Gov. Bruce Rauner signed.
The Republican OK'd the measure for small backseat passengers Friday.
Rear-facing restraints are recommended by the American Academy of Pediatrics.
Children taller than 40 inches or weighing more than 40 pounds are exempt.
Rep. Emanuel "Chris" Welch is a sponsor of the legislation. The Hillside Democrat says it replaces a law that merely required motorists to provide an "approved" safety seat for children under 8.
The initial plan in the Senate by Tinley Park Democratic Sen. Michael Hastings hit a snag because it included a $75 fine for first-time offenders. Lawmakers found that unfair. Welch says the law leaves penalties to authorities' discretion.