Ford has finally shed some light on the scale of the delays it’s experiencing in rolling out its first mass-market electric car, the Mustang Mach-E SUV. After the company announced on Wednesday that it shipped 3,739 Mustang Mach-Es in February — the first full month of deliveries — it told The Verge in a statement that some 4,500 customers will have to wait longer than expected to receive the electric SUV.

The automaker didn’t say specifically what’s causing the delay, just that it’s holding back the electric Mustangs “as part of our commitment to deliver a quality vehicle to customers.” Ford previously said in January it was delaying the delivery of “several hundred” of them for quality checks.

To help make up for the delay, Ford is giving affected customers an extra 250kWh of free charging at stations that are in the company’s FordPass Charging Network. (Buyers of the Mustang Mach-E were already getting 250kWh free as a promotion.) Ford also says it “will cover the first month’s payment” — up to $1,000 — “for approximately 250 customers experiencing extended delays receiving their Mustang Mach-E.” News of these accommodations first bubbled up in a Mach-E forum on Tuesday.

Ford’s not alone in experiencing trouble with the launch of an EV. Earlier this week, The Verge first reported that Volvo is holding a number of XC40 Recharge SUVs at US ports in order to ship a software update before the electric vehicles get to customers. Volkswagen also ran into trouble during the launch of its ID 3 mass-market EV last year because of a software issue.

Ford also had trouble rolling out a new version of the Explorer in 2019, which led to a shakeup in the company’s executive ranks that was a precursor to Jim Farley replacing Jim Hackett as CEO.