Serena Williams is keeping it real when it comes to her postpartum wardrobe.

The 42-year-old tennis legend — who welcomed her second child with husband Alexis Ohanian in August — shared her struggle getting back to her “goal” weight with fans as she posted a video on Instagram Sunday captioned “The Diary of a Denim skirt (part 1) #valentino.”

“I got this cool Valentino skirt when I was pregnant and I was like ‘I’m gonna be able to fit this when I don’t have a belly,’” Williams said in the clip.

However, she admitted, “I can’t fit it” as she showed the long denim skirt to the camera.

“But this is my goal,” the retired tennis star added, admitting she “should’ve been able to fit it by now” but that she “got distracted for about a month.”

“I’m about a month behind,” Williams — who wore a black Nike playsuit — said with a laugh as she attempted to pull the skirt over her booty to no avail.

“We have a ways to go,” she said, quipping, “Houston, we got a problem! Palm Beach, we got a problem!”

The Wimbledon champ wriggles around in the skirt, continuing, “I feel like if I go to the gym and get fit, I’ll be able to fit it again.”

The camera then pans in on the skirt with text reading “Back to the drawer … for now!”

While fans supported her fitness journey, they also jumped in to support the tennis star, like one who wrote, “Houston disregard… that ain’t no problem .”