Bill Clinton will back gay rights in a televised message this week to mark the first anniversary of the repeal of the Defense of Marriage Act (DOMA).

The former President will appear in a special message on Thursday to introduce Trailblazers, a documentary on Logo, marking one year since DOMA was struck down. Clinton will say that he was “honored and grateful to be among the voices urging” the repeal of the act, which barred federal recognition of same-sex marriages.

It was in fact Clinton himself that signed DOMA into law in 1996, but changed his mind on the issue. Before the Supreme Court’s ruling last year, he wrote in The Washington Post that “as the president who signed the act into law, I have come to believe that DOMA is contrary to those principles and, in fact, incompatible with our Constitution.”

Trailblazers will pay tribute to two key figures in the DOMA case: the plaintiff, Edith Windsor; and a lawyer, Roberta A. Kaplan. Discussing those two women, Clinton will say in the video message, “As marriage equality spreads across the states, the number of people impacted by these two amazing women will only continue to grow.”

The documentary, timed to coincide with Pride Month, will also honor NBA player Jason Collins, the first publicly gay athlete in a major US sport; John Abdallah Wamere, a gay rights activist and Ugandan refugee; and others.