Kate Middleton reportedly wears two different shoe sizes depending on the brand that she’s using. The Duchess of Cambridge’s heels is usually 38.5 or 39 in size.

During a red carpet event, Kate was photographed in her Jimmy Choo Georgia heels in 38.5, but if the mom of three is wearing L.K. Bennett shoes, she usually gets them size 39. The reason for her two different shoe sizes has to do with the fact that not all brands have the exact same measurement.

According to Hello! Magazine, there is no doubt that Kate wears different sizes of shoes for comfort reasons, and she’s not the only member of the royal family who does this trick. Meghan Markle also wears different sizes of shoes depending on the brand that she’s using.

During one of her outings, the Duchess of Sussex stepped out in her nude Aquazzura Matilde, which looked a little too big for her. She also wore another pair of shoes that looked a little too big at last year’s Royal Ascot. The publication’s fashion editor, Rachel Story, said that buying different sizes of shoes is not actually uncommon among A-listers and royals.

“Celebrities often size up for red carpets and for events — mainly to avoid blisters,” she said. “Plus, it’s all about how the shoe feels when you try them on and walk around in them, rather than sticking to what size you normally take. Italian shoes often run bigger — I always take a half size smaller. So, that could be the case for why some styles, such as Aquazurra, are large on Meghan,” she explained.

Meanwhile, there’s also another trick that Kate and Meghan may have been doing for the sake of comfort. According to Story, some celebrities stuff their toes with padding-like cotton wool so that they could walk in heels for very long periods of time. The good thing about this shoe hack is that the padding can be taken out whenever necessary.

In fact, wearing heels may have been so comfortable for Meghan that she has also worn them throughout her entire pregnancy.

Kate Middleton Catherine, Duchess of Cambridge, visits the Foundling Museum to understand how they use art to make a positive contribution to society by engaging with vulnerable and marginalized young people. Eddie Mulholland-WPA Pool/Getty Images