The U.S. House on Wednesday rejected a measure that would have blocked the Treasury Department from implementing guidelines to make it easier for legal marijuana businesses to conduct banking.

Because marijuana is still illegal under federal law, banks who conduct business with marijuana-related companies could be accused of helping them launder their money, according to the Associated Press. A conviction on charges of federal money laundering can result in decades in prison.

Earlier this year, the Obama Administration provided banks with federal guidelines for conducting banking transactions with legal marijuana sellers, enabling a legalized marijuana industry to operate in states that approve it. Representative John Fleming of Louisiana had proposed a measure to block the Treasury Department from implementing the guidelines. The House rejected the move, the AP notes.

Legal marijuana sellers that are barred from utilizing banks cannot safely deposit cash, leaving them vulnerable to criminals and robbery. Also, state governments that allow marijuana sales want a channel to properly receive taxes from legal marijuana businesses.

“You cannot track the money,” said Representative Ed Perlmutter of Colorado. “There is skimming and tax evasion. So the guidance by the Justice Department and the guidance by the Treasury Department is to bring this out into the open.”