Apple and its main contract manufacturing firm Foxconn have agreed to tackle violations of conditions among the 1.2 million workers assembling iPhones and iPads in a landmark decision that could change the way Western companies do business in China.

Taiwan’s Foxconn Technology Group, whose subsidiary Hon Hai Precision Industry assembles Apple devices in factories in China, will hire tens of thousands of new workers, eliminate illegal overtime, improve safety protocols and upgrade workers’ housing and other amenities. It is a response to one of the largest investigations ever conducted of a US company’s operations outside of America. Apple had agreed to the investigation by the independent Fair Labor Association to stem a crescendo of criticism that its products were built on the backs of mistreated Chinese workers.