The royal family committed an embarrassing blunder in their birthday greeting for Prince Louis this week.

On their official Twitter account, the royal family called the 2-year-old the Queen’s seventh great-grandchild. However, Prince Louis is the Queen’s sixth great-grandchild.

Prince William and Kate Middleton’s youngest child was born two months before his younger cousin, Lena Tindall. Since the royals’ birthday is quite close to each other, this could be the reason behind the confusion.

“Happy Birthday to Prince Louis. HRH is the Queen’s seventh great-grandchild. Today he turns two!” the tweet read.

Some royal fans couldn’t help but correct the embarrassing mistake. Most of them stressed the fact that Lena was born on June 18.

The Queen has eight great-grandchildren. Her eldest great-grandchild is Savannah Phillips, 9. She is the daughter of Peter Phillips and Autumn Kelly.

Savannah’s younger sister, Isla, 8, is the Queen’s second great-grandchild. She is followed by Prince George, 6, Mia Tindall, 6, Princess Charlotte, 4, Prince Louis, 2, Lena, 1, and 11-month-old, Archie.

Meanwhile, Prince Louis also made headlines this week after he made an appearance alongside his parents and siblings in BBC One’s “The Big Night.” The Cambridges took part in a comedy sketch alongside comedian Stephen Fry.

The segment opens with Fry waiting to receive a phone call from Prince William via Zoom. During the first few seconds of their conversation, the two men discussed some of the challenges of living in isolation.

Prince William jokes that he’s is unable to watch the soap opera “EastEnders,” and Fry suggests that he watch “Tiger King” on Netflix.

The Duke of Cambridge tells Fry that he should avoid watching shows about royalty even though he didn’t mention which shows exactly he’s talking about.

After hanging up the phone, Prince William steps out of his home and joins his wife and kids as they clap for the front liners.

Middleton is carrying her 2-year-old son in her arms while they both clap loudly for those who have been risking their lives to save others.

The Cambridges dons color-coordinated outfits in the video. Prince William is wearing purple polo shirt and a matching sweatshirt. Middleton is wearing a purple floral dress, while Prince Louis is wearing navy-blue shorts and a sweatshirt. 

Prince George and Princess Charlotte look adorable in their clothes. The 6-year-old is wearing navy-blue trousers and a checkered polo shirt. Princess Charlotte, on the other hand, is wearing a blue floral dress. Her hair is tied in a neat pigtail.