Bad news doesn’t seem so bad when it’s delivered in a personalized message from Dwayne “The Rock” Johnson — especially if you’re his “biggest fan.”

The bad news? Johnson is busy on May 5, so he can’t make it to Stillwater Area High School’s prom, but he has another outing in store for 18-year-old superfan Katie Kelzenberg, who recently asked him to the big dance on Twitter.

The celebrity’s surprise came courtesy of the school’s morning announcements Friday while Kelzenberg sat in an Advanced Placement statistics class. Johnson said he can’t make the prom because of a filmshoot, but he revealed that he’s rented out Marcus Oakdale Cinema so Kelzenberg and 232 of her closest friends and family can see his new flick, “Rampage,” for free. The Rock is also picking up the tab for “all the popcorn and candy and soda” they can stomach.

It took only seconds for Kelzenberg’s mouth to fall open and her hands to fly to her face after Johnson’s deep voice filled the classroom. The school captured the senior’s reaction and shared it Friday on Facebook, where it had amassed more than 280,000 views by Friday evening.

“All right,” Johnson intoned over the intercom, “let’s start this Friday morning announcement off with a little bit of fun and a little bit of excitement.”

Kelzenberg, of Afton, said she was working on math homework when she heard her favorite actor’s voice.

“I was like, ‘Who’s talking?’ Then I was like, ‘Oh my gosh, it’s the Rock,’ ” she recalled in an interview Friday. “Then, he says my name.”

And that’s when Kelzenberg started crying.

Johnson’s message continued: “Katie, I’m sure that you are so embarrassed right now, but I just had to let you know, I appreciate how cool and awesome you are for inviting me to your prom.”

It’s the kind of thoughtful gesture that made Kelzenberg idolize Johnson in the first place, she said.

“The way he interacts with his fans is so wonderful,” she said. “He doesn’t need to take time out of his day to do all this stuff, but he does. It shows what kind of person he truly is.”

Johnson also posted a video on Instagram on Friday, praising Kelzenberg’s moxie for asking him.

Kelzenberg described her “promposal” Twitter video as “maybe one of the most outgoing things I have done.”

Since the celebrity is tied up on prom night, Kelzenberg said she plans to go with friends and already has a blue dress picked out for the dance. But Johnson will still be there in spirit — and in cardboard.

The senior plans to take a 6-foot-3 cutout of Johnson to prom. Their wardrobes, she admits, may clash. While she’s in her blue finery, her cardboard escort will be in his beach attire from his recent film “Baywatch”: red swimming trunks.