A Republican senator plans to introduce legislation to close what he calls a welfare “loophole” after the Department of Health and Human Services confirmed it had “no authority” to prohibit recipients from using their benefit cards at marijuana stores in states where pot is legal.

Sen. Jeff Sessions, R-Ala., released a letter he received over the summer from HHS Secretary Sylvia Burwell. In it, the secretary said that while Washington can punish states for letting welfare recipients use benefits at liquor stores and casinos and strip clubs, marijuana stores were “not included” on the list of establishments where the benefits are banned.

“The federal government [currently] spends roughly $750 billion each year on means-tested welfare programs across 80 different accounts,” Sessions said in a statement. “This money is administered by a vast, sprawling bureaucracy with little oversight and no moral vision. Surely we can all agree that the guiding principle ought to be that benefits are reserved for those in real need.”

He said he plans to introduce a bill to “address this problem.”

The letter from Burwell came in response to an inquiry Sessions sent in April about the possibility that residents in Colorado and other states where recreational marijuana is legal or decriminalized could use welfare benefits to buy the drug.

The HHS letter noted media reports that recipients in Colorado were found to be withdrawing cash at ATM machines at marijuana dispensaries.

“I agree that any inappropriate expenditure of public funds is a cause for concern and should be addressed immediately,” Burwell wrote.

Burwell said that while the feds are limited in their authority, states can take action on their own to restrict the use of benefit cards at marijuana shops. She noted that Colorado state lawmakers were looking at legislation to bar withdrawals of welfare benefits at marijuana shops.