Foxconn has been employing students illegally to work overtime at its factories to assemble the iPhone X, reports the Financial Times. Six high school students told the publication they regularly work 11-hour days assembling the device, which is illegal for student interns under China’s laws. The students were between 17 to 19 years old, and said they were told they had to work at the factory for three months as a requirement to graduate. One student told the FT they were being forced to work there, and that the work had nothing to do with their studies. The student also claimed to have assembled up to 1,200 iPhone X cameras a day.

According to the FT, Apple and Foxconn said they had discovered cases of student interns working overtime, and they were taking remedial action. However, both companies also claimed that the students were not “forced” to work beyond the legal hourly limits. “We’ve confirmed the students worked voluntarily, were compensated and provided benefits,” Apple said. “But they should not have been allowed to work overtime.”

Similarly, Foxconn said it worked with local governments and vocational schools in organizing the internship program, but acknowledged the overtime work violated its policy that prohibits students from working more than 40 hours a week. Today’s news comes after reports of high iPhone X demand ahead of the device’s intended ship date, which were compounded with rumors of production delays due to supply problems.

At least 300,000 people assemble iPhones at Foxconn, with 3,000 students from Zhengzhou Urban Rail Transit School sent to help with the iPhone X. The six students the FT spoke to volunteered to work overtime and were paid illegally for it. Though it still doesn’t look good for Apple or Foxconn, given this context, the situation pales in comparison to the extreme conditions previously reported at Foxconn.