Deliveries of its GT supercar aren’t going as smoothly as Ford had anticipated.

The automaker, in a letter sent to some customers waiting for their GT, said, “The craftsmanship required to build these vehicles for global markets has required that we adjust our original timing projections.”

Ford didn’t say how long the delays would be, but in its letter the automaker said it would provide a new 3-month projected delivery window within a week.

According to Automotive News (subscription required), the cause of the delays are supplier constraints, and homologation testing issues for certain markets.

Once the issues are sorted, Ford hopes to build the GT at a rate of one per day. The cars are being built by race car constructor and carbon fiber expert Multimatic at a plant in Markham, Ontario, Canada. You can get a taste of what it’s likely building the GT in this video.

Ford is scheduled to build 250 GTs per year over four years. So far the company has allocated build slots for the first two years only. An application process for the remaining build slots will be announced at a later date.

Ford has delivered about 50 GTs since production started last December. Four recipients we know of are Ford Chairman Bill Ford Jr., ex-Ford CEO Mark Fields, Jay Leno and Jack Roush. They have cars number one, two, 12 and 15, respectively.