Calling it a truce? Justin Bieber and Taylor Swift may have just ended their years-long feud. The "What Do You Mean?" singer posted a video of himself singing Swift's breakout 2006 hit "Teardrops On My Guitar" — and she reacted.

Bieber, 22, sits and sings in the passenger seat of a car in the clip, which he shared via Instagram on Monday, May 23. Swift, 26, noticed the possible olive branch and liked the post.

It's been a while since Swift and Bieber were on good terms. In August 2013, Us Weekly exclusively revealed that Bieber's on-again, off-again relationship with Swift's BFF Selena Gomez drove a wedge between them.

"Taylor hates him. She thinks Selena makes a mistake every time she reconciles with him. Bieber has really come between the girls," a source told Us at the time.

A Bieber insider added: "He complains Taylor's always telling Selena she can do better." (Swift would stick by Gomez's side through their second split in November 2014.)

Swift has alluded to their beef before. In May 2013, she refused to answer a question about Bieber in the Billboard Music Awards pressroom. "Can we have another question?" she said. Backstage, she was also caught on camera looking disgusted as Gomez, 23, kissed Bieber on the cheek.

Bieber and Swift weren't always frenemies. The two happily sat next to Gomez during the American Music Awards in 2011. The following year, Bieber pulled a prank on Swift on MTV's Punk'd.

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