On Wednesday afternoon, Treasury Secretary Jack Lew announced that the Treasury will keep Alexander Hamilton on the front of the $10 bill, a reversal of his previous statements that he was considering replacing Hamilton with a woman. The new plans will also put women’s suffrage movement leaders on the back of the bill, and—more dramatically—give Harriet Tubman the prime spot on the $20 bill, where she will replace President Andrew Jackson. According to Politico, the new designs for the $20 bill are expected to be ready by 2020.

The reaction to the news has been mostly positive, focusing on the selection of the famed civil and women’s rights activist. Democratic presidential frontrunner Hillary Clinton, TV producer Shonda Rhimes, and actress Jane Lynch were just a few of the high-profile women celebrating the news on Twitter:

A woman, a leader, and a freedom fighter. I can't think of a better choice for the $20 bill than Harriet Tubman: https://t.co/YcsZC4ZrKg -H

— Hillary Clinton (@HillaryClinton) April 20, 2016

We got a $20 Freedom Mama Without the Drama of messing with the $10 Founding Father Without a Father. #hamilnerd @Lin_Manuel

— shonda rhimes (@shondarhimes) April 20, 2016

.@USTreasury I am so dang proud to be on this letter demanding a woman fronts #TheNew10 https://t.co/5a6JVBQV4T #NotGoingBack

— Jane Lynch (@janemarielynch) April 20, 2016

The letter Lynch refers to in her tweet is an open letter to Sec. Lew released on Wednesday morning by women’s leadership platform MAKERS. Published before the news of the Treasury’s announcement broke (and before the plans to put Tubman on the $20 were made public), the note is less than enthusiastic about the idea of relegating women to the back of the $10.

“Think of what kind of message you’d be sending our daughters by going through with the rumored interim step of putting a woman on the back of the $10 bill,” reads the letter. “Could there be a better metaphor for the second-class status that continues to limit our girls?”

The signatories of the letter include talk show host Ellen DeGeneres, media mogul Arianna Huffington, women’s rights activist Gloria Steinem, anchor Katie Couric, and U.S. soccer star Abby Wambach, among others.

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The MAKERS team is also concerned with how long it will take to redesign the $20, pointing out that the move “would require up to a decade of additional work” and thus “would undoubtedly be a major blow to the advancement of women.”

Even with the knowledge that Tubman will be on the $20, Susan Ades Stone, executive director of the activist group Women On 20s, shares this more skeptical sentiment. “In recent days reliable sources were telling us we wouldn’t see the redesigned $20 until 2030,” she writes in a statement after the Treasury announcement. “Assuming this is true, we see today’s announcement as only a vague commitment and a continuation of the now familiar message that women have to settle for less and wait for their fair share.”

Despite the prolonged timeline of the redesign, the choice of Harriet Tubman is an “exciting” one, writes Stone. “Not only did she devote her life to racial equality, she fought for women’s rights alongside the nation’s leading suffragists.”