CNN’s Don Lemon aired old footage of President Donald Trump bragging about his vast knowledge of campaign finance on Wednesday night.

“I think nobody knows more about campaign finance than I do because I’m the biggest contributor,” Trump boasted to then-late-night TV host Larry King in the clip from 1999.

“CNN Tonight” host Lemon chuckled at the vintage footage before channeling cartoon character Scooby Doo in response. “Ruh-roh,” he said, mimicking what the fictional dog says when things begin to go awry.

“Sounds like Donald Trump knows plenty about campaign finance, a fact that could certainly backfire on him,” Lemon added. “There’s always a tape or a tweet for everything. Did you notice that?”

Trump’s former personal lawyer, Michael Cohen, has been sentenced to three years in prison after pleading guilty to a slew of crimes —including violating campaign finance laws, which he claimed was at the behest of Trump himself.

Check out the clip here: