Customer satisfaction with dealer service declines for the first time in six years, according to the J.D. Power 2016 U.S. Customer Service Index (CSI) Study.

The drop in satisfaction this year, which comes on the heels of a record number of recalls, stems from customers feeling that dealers do not give the same level of attention to recall work as they do to non-recall maintenance and repairs.

The study measures customer satisfaction with service at a franchised dealer facility for maintenance or repair work among owners and lessees of one- to five-year-old vehicles.

More than 51 million vehicles were recalled in 2015, according to the National Highway Traffic Safety Administration (NHTSA). As recall numbers increase, customer satisfaction with recall service drops to 781 on a 1,000-point scale in 2016, down from 789 in 2015.

In comparison, satisfaction among customers with non-recall servicing averages 809 in 2016, according to the study.

Compared with customers having non-recall work performed, those having recall work done are less likely to have their vehicle returned to them cleaner and with the same settings as when they brought it in. They are also less likely to be contacted by the dealer after the service is complete.

“While it may be tempting for dealers to focus more on repair or maintenance work, recall customers represent both an opportunity and a risk to the brand and dealer,” said Chris Sutton, vice president, U.S. automotive retail practice at J.D. Power. “There is a need for consistency in the service experience, regardless of the reason for the visit. A lack of consistency, particularly for recall work, can damage customers’ perceptions of the brand and negatively impact their likelihood to recommend and repurchase the brand.”