A new feud is brewing between Donald Trump and another celebrity. This time, Jerry Seinfeld is the one finding themselves in the real estate mogul’s crosshairs. Trump directed heated remarks at Seinfeld after he pulled out of a fundraiser for St. Jude Children’s Research Hospital.

The fundraiser was scheduled to be hosted by the Eric Trump Foundation on September 13. Seinfeld canceled his scheduled appearance because he personally disagrees with Trump’s allegations that President Barack Obama is not actually a U.S. citizen.

Trump lashed out, expressing his disappointment toward Seinfeld in canceling on his son and the children of St. Jude Children’s Research Hospital. Seinfeld originally agreed to the appearance in January before Trump begin making moves toward a possible run for president in 2012 and spouting rhetoric against President Obama. In place of appearing at the event, Seinfeld plans to make a donation to the foundation and the hospital.