Analysts have reported doubt that Apple will reach its goal of selling 10 million iPhones this year, though the popular technology company has said it stands by its previously stated benchmark.

In a recent report, Bernstein Research Analyst Toni Sacconaghi warned that while the iPhone could prove a crucial part of the company’s future earnings, issues such as unlocked devices and falling demand could spell trouble for Apple.

“Apple’s goal of selling 10 million iPhones this year is optimistic, particularly if Apple insists on carrier revenue sharing without significant price cuts or new model introductions,” Sacconaghi wrote in his report.