This post is part of the #kidlitwomen initiative. We’re celebrating Women’s History Month with 31 days of posts focused on improving the climate for social and gender equality in the children’s and teens’ literature community. Join in the conversation on Facebook or Twitter.

I’ve always loved snuggling up with a good book, and now that I’m a mom to a toddler, I love it even more. There’s not much I can think of that’s nicer than letting my daughter crawl into my lap, drawing a blanket around us both, and reading stories together. When we point at objects we recognize in the illustrations, talk about the characters, and recite our favorite lines from memory, I hope I’m teaching my daughter to love books just as much as I do.

Sometimes, though, I wonder if she’s learning unintended lessons from the books we share. In more than a few of the stories we’ve read together, most of the characters are male. Sometimes they’re all male. In one recently published book we love about animals at a zoo, every character in the book—animal and human—is identified in the text with male pronouns. The first time we read that book together, I was genuinely surprised it hadn’t been written decades ago. None of us live in an entirely male world. There are women in our lives, whether they’re our mothers, siblings, children, friends, colleagues, mentors, or enemies. There are genderqueer and nonbinary people in our lives, too. In a world as diverse as ours, if you write a book in which the vast majority of characters are male, you are making a political statement whether or not you intend to.

And most of us don’t intend to. All of us who’ve been raised in American culture have been taught—implicitly if not explicitly—that the “default” gender is male. This is a bias that anyone of any gender can hold. I notice it in my own thinking constantly: when I’m reading wordless picture books with my daughter and we’re pointing out the animals in the illustrations, I have to consciously remind myself not to call them all “him.” Holding this bias doesn’t make me a bad feminist, a bad writer, or a bad person; it’s a reflection of the culture I’ve grown up in, and it makes me want to work as hard as possible to change that culture for today’s and tomorrow’s readers.

If you’re a writer who feels the same way, I hope you’ll join me in making a conscious effort to notice the characters who populate our fiction. Take a close look at your cast: not just the protagonists, but also the people wandering around in the background of your story. If you’ve written a book with a fantastic female protagonist surrounded mostly by men, you have more work to do. If your only female characters are love interests, or if they’re described only in terms of their relationship to the men in the story, you have more work to do. If you’ve written a book full of characters who hew to gender stereotypes, you have more work to do. If you describe a strong, smart, brave female character as being “not like other girls,” you have more work to do. Challenge yourself to introduce a non-male character with a speaking role in the first chapter of every book you write. Challenge yourself to write only books that pass the Bechdel test. If a character’s gender isn’t an important part of their role in your story, don’t automatically make that character male. Remember that not everyone identifies as male or female; that gender doesn’t determine a person’s interests, skills, or qualities; and that kids of all genders will be reading your stories and learning unintended lessons from them. I’m doing this tough work right alongside you. Let’s help one another change the default.