Supporters of the decision by the Obama White House to put the black abolitionist Harriet Tubman on the front of the $20 bill are worried that it could be reversed.

“We certainly are worried, when [Donald] Trump won the election, that he might try to make good on his suggestion that Harriet Tubman be put on the $2 bill instead of the $20 bill,” said Susan Ades Stone, executive director of the nonprofit organization Women on 20s. “It would be a slap in the face of women to reverse the decision in our opinion.”

Lisa Maatz, vice president for government relations at the American Association of University Women, also expressed concern. She said that Trump should consider he has a “credibility gap” with women before deciding to reverse the decision.

During the presidential campaign, Trump said he thought it was “very rough” to take Andrew Jackson off the $20 note.

“I think it’s pure political correctness,” Trump said during an April appearance on NBC’s “Today” show, suggesting that Tubman, who he allowed “is fantastic,” be placed on another denomination. “Maybe we do the $2 bill or we do another bill,” Trump suggested. (Thomas Jefferson appears on the $2 bill, which remains in circulation and production.)

See:Hamilton to stay on $10 bill, with Harriet Tubman replacing Andrew Jackson on $20 bill

Treasury officials would not comment on whether Trump would or could scuttle the Tubman plan.

Asked shortly before the election whether Tubman could be blocked from the $20 bill, Treasury Secretary Jacob Lew avoided giving a direct answer but noted there had been widespread support for the redesigned currency. “I think the enthusiasm about the announcement and what we’ve made has left an important mark. ... [P]eople have already started calling them ‘Tubmans,’ and they’re not even printed yet.”

The Trump press office did not respond to a request for comment.

In April, after a lengthy selection process during which 1.5 million Americans reportedly sent in suggestions for new currency designs, Lew announced that Tubman would replace Jackson.

Read: From Pocahontas to Tubman: Watch U.S. currency transform over the years

Work on security measures and design is underway at the Bureau of Printing and Engraving. The final design of the $20 bill won’t be ready until 2020, with issuance to follow. The Treasury is planning to push out newly designed $10 and $5 bills first because those bills need new security features.

“The further along they are in design, the harder it will be for someone to say, ‘Stop the presses, we’re starting over,’ ” Ades Stone said.