People passing by St. Mary's Lindo Wing spotted one small but telling detail.

Catherine Duchess of Cambridge
Credit: Geoff Pugh - WPA Pool/Getty Images

The hospital where Kate Middleton is expected to deliver her third royal baby appears to be in nesting mode.

The Lindo Wing at St. Mary's Hospital, where the Duchess of Cambridge also gave birth to Prince George and Princess Charlotte, has been sprucing things up for the impending royal arrival. As several people spotted while passing by, the hospital appears to have given the railings along the outside steps a fresh coat of paint.

The new paint is leading many to believe that Kate and her husband, Prince William, are expecting their third child sooner than we all thought.

"The railings outside The Lindo Wing at St Marys Hospital Paddington are being painted. I suppose it’s never too early to get used to the smell of fresh paint," Arthur Edwards, a royal photographer for The Sun, tweeted.

Though it may seem like a small detail, painting the railing is a key part of the baby prep as Kate and William will almost certainly debut their new baby on those very steps, as they did when she gave birth to Prince George in 2013 and Princess Charlotte in 2015. As Elle explained, Princess Diana also did the same when she gave birth to both Prince William and Prince Harry.

According to reports, Middleton is expected to give birth on April 23, though really, it’s anyone’s guess. Kensington Palace confirmed the baby is due in April, and the Duchess is officially on maternity leave. She completed her final royal appearance on March 22, so now all she needs to focus on is giving birth to a happy, healthy baby.

Then, she can turn her attention to helping her brother-in-law Prince Harry with any last-minute wedding prep before he walks down the aisle to marry Meghan Markle. After all that, hopefully all the royals will take a much needed, and highly deserved, vacation.