With the passage of Prop. 2 this month, Alaska joins Colorado, Washington, Oregon and the District of Columbia in legalizing marijuana. While the state figures out how to regulate marijuana commerce, several federal laws sit as roadblocks to the business of cannabis.

Alaskans who hope to operate marijuana businesses will have to defy U.S. drug law, of course. But they’ll also face other federal rules they’re likely to find severely inconvenient and perhaps crippling to their enterprise.

One problem is a bit of tax code called 280E. This provision, enacted in the 1980s, prevents narco-traffickers from deducting business expenses, and the IRS enforces it against state-licensed pot businesses, too. Taylor West, deputy director of the Denver-based National Cannabis Industry Association, says it means marijuana businesses can’t deduct costs like rent and payroll when they file their tax returns.

Read more: Marijuana Entrepreneurs Face Special Business Burdens | Alaska Public Media