(CNN) Oh, dear. How ever could they have missed this during their promenade around the town square?
Some fans of the hit Netflix series "Bridgerton" noticed a bit of modern scenery in the Regency era drama.
"Two episodes into #Bridgerton and I've so far spotted a single yellow line and a telecoms manhole cover," one eagle-eye viewer tweeted. "I didn't realise the 19th Century Brits were such pioneers..."
Indeed, dear reader, the notion of yellow lines on the road didn't originate until the 1940s, according to a 1997 article from the Independent, a UK newspaper.
Another viewer tweeted that he spotted posters for the retail chain, Primark, in some windows featured in the show's scenes.
The chain opened in 1969.
"Bridgerton" is based on the first in a series of romance novels by Julia Quinn.
Netflix has announced the show will return for a second season.