CNN — More than a year after Hyundai and Kia released new anti-theft software updates, thefts of vehicles with the new software are falling, according to a new analysis of insurance claim data.

The automakers released the updates starting last February, after a tenfold increase in thefts of certain Hyundai and Kia models in just the past three years — sparked by a series of social media posts that showed people how to steal the vehicles.

“Whole vehicle” theft claims — insurance claims for the loss of the entire vehicle — are 64% lower among the Hyundai and Kia cars that have had the software upgrade, compared to cars of the same make, model and year without the upgrade, according to the Highway Loss Data Institute.

“The companies’ solution is extremely effective,” Matt Moore, senior vice president of HLDI, an industry group backed by auto insurers, said in a statement.

The cars in question are certain older Hyundai and Kia models made before 2023 that are particularly vulnerable to theft. Less expensive versions of these vehicles were equipped with turn-key ignitions rather than a button-press to start, and they’re roughly twice as likely to be stolen as other vehicles of a similar age, according to the HLDI.

Many of these vehicles also lack some basic auto-theft prevention tech, such as electronic immobilizers, included in most other vehicles made the same years, says the HLDI. Immobilizers rely on a computer chip in the car and another in the key that communicate to confirm that the key is authentic and really belongs to that vehicle.

Between early 2020 and the first half of 2023, thefts of Hyundai and Kia models rose more than 1,000%.