Kraken paid 250 salaries to staff in bitcoin (BTC) last month, the crypto exchange revealed in a tweet on May 23.

The firm was responding to Peter Schiff, the CEO of Euro Pacific Capital, who had claimed “there is no way that people are going to work for salaries paid in bitcoin.”

As an aside, Kraken added:

“By the way, the employee who took 100% bitcoin in 2012 retired in 2013.”

Kraken reportedly employs about 800 people. While this figure suggests about 30% of its workforce are being paid in cryptocurrency, there could be some way to go before it is commonplace in the company.

Across the industry, there are some hurdles in place that can stop employers from offering crypto salaries at all. For example, in the United States, workers must be paid to some extent in cash or checks — and it is still unclear in many countries how such earnings should be taxed. Price volatility is another concern, as BTC’s value could rise or fall dramatically in the hours after a salary has been paid.

Last month, a former Kraken employee announced he was suing the firm for $900,000, alleging that the exchange had failed to pay him for his work there.