No one expected much from Sisters, as it opened against Star Wars: The Force Awakens, but it managed to not entirely face-plant by taking in $13.4 million over the weekend. Even though it opened #3 behind Star Wars and Alvin and the Chipmunks: Road Chip, making it into double digits is a win. It did better than recent bromantic comedy The Night Before, which is a little baffling because The Night Before is a WAY better movie. Sisters has its charms—chiefly in the form of Tina Fey and Amy Poehler—but it’s not very good. This makes the second time Fey and Poehler have fronted a movie together (see also: Baby Mama), and it’s the second time the material has fallen short for the stars. Maybe next time, let Fey and Poehler write for themselves.

Reversing their Baby Mama dynamic, this time it’s Fey playing the wild child, Kate, and Poehler playing the buttoned-up one, Maura. That works out fine for Poehler, even if at times Maura feels like Variations on a Theme of Leslie Knope, but it doesn’t work so well for Fey, who is never believable as a blowsy, trashy, mess. She’s obviously having fun playing the part, though, and can at times make it work well enough to sell a joke—a bit about tampons and pads with Maya Rudolph is especially funny. But Sisters would probably be 37% better just by switching the casting around. Poehler is the stronger actress and could probably turn Kate into a proper character, and not a caricature like Fey.

The plot is fairly straightforward. Both Kate and Maura are heading home For Reasons, but they discover that their retiree parents have sold the house out from under them and moved into a retirement home condo. James Brolin and Dianne Wiest are game as parents Bucky and Deana, and in a nice piece of writing, they’re portrayed as loving, sexually amorous partners. (The sisters have the predictable “ew yuck” response to their parents having sex, but the movie itself does not share their value judgment. The jokes, which are not as sharply drawn as they could be, lie in their bonehead daughters’ reactions, not the actual fact of their active sex life, which dares to assert that older folks are entitled to enjoy sex, too.) In a fit of pique and petulance, the sisters decide to throw one last kegger at the house and invite all their old high school friends.

The script comes from longtime Saturday Night Live writer Paula Pell, and though Sisters is basically just Step Brothers For Chicks, the humor is often drawn from uniquely feminine perspectives. Many of the jokes depend on the characters delivering them being female, which means it’s not perfectly interchangeable with the masculine version of this kind of gross out comedy. That’s nice to see, and though Sisters doesn’t combine comedy and actual emotional payoff as well as Bridesmaids did, it does, like Bridesmaids, show that there is real comedic value in mining the female experience.

But problems plague Sisters more than laughs do. At 118 minutes, it’s WAY too long, and director Jason Moore (Pitch Perfect) has zero visual flair—this movie is flat-out ugly at times. The supporting cast is good, but whether or not you laugh at their characters depends entirely on your tolerance for awkward humor. Maya Rudolph is the standout as Kate’s high school nemesis, but Rachel Dratch and Bobby Moynihan both play nerdy/awkward characters with recurring gags that play to diminishing returns. Ike Barinholtz (The Mindy Project) makes a case for being cast in a real rom-com, and John Cena pops by to prove that his turn in Trainwreck wasn’t a fluke—he doesn’t have the overwhelming charisma of The Rock, but he has decent enough chops to forge a similar post-wrestling career.

But nothing in Sisters adds up to a consistently funny movie. There are some really great joke-names, like “Brinda”, “Brayla”, and a dog named “Polenta”, but it ought to tell you something about this movie that I remember NAMES as being funnier than most of the jokes. There’s always pleasure in watching Fey and Poehler work together, and they make this material work well enough to earn some real laughter. But the movie goes on far too long, killing momentum as scenes and bits drag on, and the obligatory emotional payoff at the end, while not nearly as sappy as it could have been, still manages to feel shoehorned in. Sisters is not the worst thing you could watch, but it can’t help but be disappointing, given the talent involved. Tina & Amy deserve so much more than this.