WATCH: Shawn Mendes Slays Impressions of Justin Bieber, Adele and More

Shawn Mendes stopped by The Tonight Show to sing a series of #FallSongs with Jimmy Fallon.

As the late night TV host read autumn-themed lyrics suggested by fans on Twitter, the singer, who just dropped his new album Illuminate, sang along with help from some familiar tunes. “Watch me sneeze until I can’t breathe/ Allergies are gonna kill me,” he sang to the tune of his own hit song “Stitches.”

Later, he also tried out two tracks about leaves to Coldplay’s “Yellow” and Adele’s “Hello.” But the best #FallSong came when Mendes sang Justin Bieber’s “Sorry.” 

Meanwhile, things got a little uncomfortable when the Canadian crooner wouldn’t stop calling Fallon “old.” At first, it was funny but after a while, it wasn’t so charming.