Vietnam is increasing financial surveillance of its growing casino industry to ensure the government gets its rightful share of the gambling spoils.

Last week, Vietnam’s Ministry of Finance released A Circular Guiding Management and Supervision of the Collection of Taxes on Casino Business Activity. The document, which was officially issued on December 29 but only now made public, is the latest plank of the government’s efforts to expand its domestic casino sector.

Among the new rules, which take effect February 12, is a requirement that casino cashiers can only use “conventional currency” to accept buy-ins from players or pay out winnings. So no gold bars, prize pigs or Bitcoin accepted (Vietnam banned all cryptocurrency payments last October).

Casinos will have to record all monetary transactions through the use of specialized software, and the collected data must be contained in revenue summaries and reported to relevant state management agencies to ensure all taxes are being paid.