At one point, iPhone launches were as predictable as the changing seasons. They launch a smartphone (iPhone 4, iPhone 5, iPhone 6), then follow up with the slightly improved "S" model (4s, 5s, 6s).

That schedule could change. According to a report from Nikkei Asian Review, Apple is going to extend the product cycle of its flagship device where a revamped version of the iPhone will launch every three years instead of two years.

The report also says that shift in cycle will start this year with the launch of a new iPhone featuring minor upgrades including an improved camera. That would mean the next major iPhone launch wouldn't happen until 2017.

Shares of Apple were down slightly in pre-market trading Tuesday.

The report says the move could have a big impact on Asian manufacturers who rely on iPhone production for their revenue.

Apple's extension of the product cycle follows a decline in iPhone sales. During its second-quarter earnings call, Apple reported the first drop in iPhone sales ever, down 13%. Apple CEO Tim Cook cited a saturated smartphone market for the dip.