Groundbreaking LGBT-friendly children’s book gets a welcome update.

The timing couldn’t better for Heather Has Two Mommies to make it back into publication, now that the US legalized same-sex marriage nationwide on June 26.

The nearly thirty-year-old children’s book, a sweetly matter-of-fact look at the daily life of a little girl named Heather, her friends, and her two lesbian mothers—Mama Jane and Mama Kate—has been recently updated by author Lesléa Newman and original illustrator Laura Cornell in a way that young readers may not even notice, but their parents most likely will:

Mama Jane and Mama Kate are now married.

The book’s illustrations have been updated to show Heather’s parents wearing wedding bands, a new detail that reflects a reality now available for all families in the US, where Newman is from. The book, which Google Books cites as the first lesbian-themed children’s book ever published, had languished out of print and was essentially unavailable since it was last published in 2009.

Ever since its first publication in 1989, Heather Has Two Mommies has been both championed by families as a much-needed dose of diversity in children’s literature and denounced by hostile critics who made it one of the American Library Association’s “most frequently challenged books” of the 1990s.

This new version, published in Australia and New Zealand by Walker Books and featuring some other minor updates to the text and illustrations, arrives just in time for a new generation of children who have never seen it. It is still a gentle, heartwarming read that any child today can appreciate.

It’s easy to forget that now that when this book was first published, not even civil unions were legal for same-sex couples anywhere in the US. But even as same-sex families worldwide gain growing acceptance, this instant classic retains its relevance, thanks to the inclusive message at its heart: “the most important thing about a family is that all the people in it love each other.”