Chinese smartphone maker Xiaomi shipped 23.16 million smartphones in the second quarter of 2017, up 70 percent on the same period last year and a record high for quarterly smartphone shipments.

“Xiaomi is once again embarking on a rapid growth trajectory,” said the company’s co-founder and CEO Lei Jun. Lei attributed the success partly to increasing investment in R&D and a comeback after supply issues last year.

According to IDC, Xiaomi – sometimes known as Mi in China – was the fifth biggest shipper of smartphones in the nation in Q1 with 9 percent of the action.