Beavers tried to have the conviction overturned on grounds that his jury had no African- American males.
Beavers says he wasn't surprised by the decision and insists he's not worried about going to jail.
He maintains that federal authorities targeted him for refusing to work undercover for them.
"I'm not worried because I exposed them. I made 'em admit that they asked me to be a stool pigeon, and that's unheard of," said Beavers.
Beavers sentencing date has been set for September 25th.
He faces up to three years in prison for each of four tax evasion convictions.