A handful of tech companies have signed onto a friend of the court brief in the case of the Colorado baker who refused to make a wedding cake for a same sex couple. TechCrunch has confirmed that so far the list includes Apple, Yelp, PayPal, Salesforce and Affirm. The brief is being circulated by the Human Rights Campaign (HRC) which expects more companies to be announced by next week. It was authored by D.C. law firm Steptoe & Johnson.

While more tech companies generally voice their support in these LGBTQ-friendly cases, Masterpiece Cakeshop v. Colorado Civil Rights Commission is a tinder box of particularly volatile social issues, particularly when it comes to interpreting the religious rights secured by the First Amendment. That could be a reason tech companies have been a bit warier in this instance, though it also could be the sheer number of social causes that left-leaning tech companies have been called to support under the Trump administration.

Earlier this year at least 54 tech companies mobilized in support of Gavin Grimm, the transgender Virginia high school student who alleged that his school board violated Title IX when it did not allow him to use the boy’s restroom. Ultimately that case did not make it before the Supreme Court and instead was sent back to a lower appeals court in Richmond, Virginia.

While there was some confusion about the last day for companies to sign on, TechCrunch has clarified that the deadline is actually Monday, October 30. We’ve reached out to a number of the major tech companies about their interest in the amicus brief and will update this list when we learn more.