(Left) Former Republican presidential candidate Ben Carson talks with Republican presidential candidate Donald Trump. (AP Photo/Lynne Sladky); (Right) Harriet Tubman, between 1860 and 1875 (H.B. Lindsley/Library of Congress via AP)

Donald Trump, front runner for the Republican presidential nomination, on Thursday spoke out against putting anti-slavery freedom fighter Harriet Tubman on the $20 bill.

His opinion was shared by Ben Carson, who dropped out of the Republican presidential race following consistent poor showings in early Republican primaries.

U.S. Treasury Secretary Jacob Lew announced this week that Tubman would replace Andrew Jackson, the seventh president and a noted slave owner, on the front of the $20 bill. Jackson will move to the back of the bill. The new currency is expected to be out in 2020.

“Well, Andrew Jackson had a great history, and I think it’s very rough when you take somebody off the bill,” Trump told the NBC’s “Today” show. “I think Harriet Tubman is fantastic, but I would love to leave Andrew Jackson or see if we can maybe come up with another denomination.”

Carson, speaking to Fox Business Network, said, “I love Harriet Tubman. I love what she did, but we can find another way to honor her. Maybe a $2 bill.”

The $2 bill, of course, is not in wide circulation.

“Andrew Jackson…was a tremendous president,” Carson went on. “I mean, Andrew Jackson was the last president who actually balanced the federal budget, where we had no national debt.”

Not every Republican presidential contender thought Tubman on the $20 bill was a bad idea. John Kasich, who is running a distant third behind Senator Ted Cruz, supported the change while campaigning on April 21.

“She wasn’t some big shot,” he said. “She became a big shot because of what she did. She saw something that she thought did not represent justice, she saw something she thought that was just patently unfair.”