An eagle-eyed Coronation Street fan noticed the return of a ex- actor in the background of a scene earlier this week.
Dev Alahan's son Aadi was recast in April after his twin sister Asha found herself at the centre of a major storyline.
Actor Zennon Ditchett was cast in 2009 and played Aadi for ten years, but decided to quit the show to focus on his A Levels at the beginning of the year.
He was replaced by actor Adam Hussain, who made his first appearance in the soap on April 15.
Both of the twins have found themselves at the centre of a big storyline which explores the devastating effect of online trolling.
A video of Asha undressing was leaked online without her permission after the 14-year-old's love interest Corey had secretly recorded her.
Kelly Neelan then found the video and posted it to everyone in school.
After initially slamming his sister, Aadi began defending Asha and became involved in fights at school.
But one fan noticed that actor Zennon could still be seen on set after spotting a picture hanging on the wall behind Dev.
The old picture showed ex-actor Zennon and Asha actress Tanisha Gorey hugging as children.
They tweeted: "Dev’s boy has changed and he hasn’t even noticed. A reminder of old Aadi on the wall. #Corrie"
*Coronation Street airs Mondays, Wednesdays and Fridays at 7.30pm on ITV
