Diane Keaton was stunned to appear in Justin Bieber’s 2021 music video for his single, Ghost.

In a new interview with Metro, the Annie Hall star said, “I couldn’t believe it when Justin asked me to appear in his video.”

In a music video, Diane was seen playing Baby hit-maker’s grandmother as the two of them grieved the loss of the actress’ fictional husband.

While talking about music video, the 77-year-old stated, “This was like one of those things that happens [and] you’re going, ‘I’m what?’”

Diane explained, “It was so much fun, it couldn’t have been more fun. I can’t believe it. I still can’t believe it.”

The actress mentioned that she “didn’t even know” Justin before filming this video.

“No, I hadn’t been a fan,” she confessed.

Diane disclosed, “I didn’t even know him. I knew the music a little and I liked the music, but I wasn’t a fan exactly – so you know, I don’t have music pouring in my ears all the time.”

“I don’t know why me; I still don’t understand. I don’t know how, but I loved it,” she added.

Meanwhile, on the work front, Diane will be next seen in Book Club: The Next Chapter alongside Jane Fonda, Candice Bergen and Mary Steenburgen. 

The movie is slated to release in theatres on May 12.