When it comes to doing business with marijuana sellers, it’s going to take a lot more than a thumbs-up from Eric Holder to get paranoid bankers on board.

The U.S. attorney general made waves last week when he said the Obama administration plans to give banks the go-ahead to make loans or open accounts for marijuana dispensaries in states where they’re legal without running afoul of federal laws, which still consider cannabis an illegal substance.

While the reassurance from Holder is nice, bankers say it’s not that simple.

Read more: Banks still wary about marijuana business | Politico