Of all the safety systems that automakers put into their vehicles, the seat belt is arguably the most essential. But they may not be working properly on some Mercedes crossovers. So the manufacturer is recalling over 120,000 of them in the United States.

The problem, according to the National Highway Traffic Safety Administration, is that the buckles may retract into the interior paneling on the outboard rear seats. That would make them rather hard to fasten, rendering them essentially useless.

The issue was found to affect GLC crossovers from the 2016 through 2019 model years. They include the GLC300 and GLC300 4Matic, the GLC350e hybrid, and both the AMG GLC43 and GLC63. They’ll need to be brought in to have a buffer installed in the C-pillar to keep the buckles in place and accessible. All told, Mercedes-Benz calculates there are 121,861 of them in the United States.

The automaker introduced the GLC in 2015 as the replacement for the previous GLK. It serves as the crossover counterpart to the C-Class sedan, wagon, coupe, and convertible. The recall does not appear to affect the GLC Coupe version, which has a different C-pillar design to support its sloped roof. But considering that Daimler sells fewer than 50,000 GLC crossovers here each year, the recall would ostensibly affect the vast majority of them.

Along with the compact crossovers, Mercedes is also recalling a handful of E-Class models to readjust their LED headlights. All of 28 examples of the 2017 model – including E300, E300 4Matic, and AMG E43 variants – are included.