Who said the magic of the holiday season has to fade come January? Keep it alive all year long with these 15 interesting facts about 1989’s National Lampoon’s Christmas Vacation.

1. Christmas Vacation is based on a John Hughes short story.

Hughes's story, “Christmas ’59,” was originally published in the December 1980 issue of National Lampoon; it was a follow-up to his original story, “Vacation ’58,” which was made into the original Vacation movie in 1983. The movie gives a small nod to Hughes’s original story when Clark pulls out reels of old family Christmas films to reveal that one is titled “X-Mas ’59.”

2. Johnny Galecki and Juliette Lewis are the third pair of actors to play Rusty and Audrey in the Vacation series.

Lewis would reprise her role in a series of Vacation-themed Old Navy commercials in 2012 also starring Chevy Chase and Beverly D’Angelo as Clark and Ellen Griswold.

3. Christmas Vacation is director Jeremiah Chechik’s first feature film.

And, he had never seen either of the previous Vacation movies before taking the job. Chechik makes a small appearance in the movie as the man on the cover of the People magazine that Clark reads in bed.

4. There were no rehearsals for the actors on Christmas Vacation.

Chase’s tendency to ad-lib and improvise made such preparation useless.

5. Christmas Vacation features four Saturday Night Live alums:

Chevy Chase, Brian Doyle-Murray, Julia Louis-Dreyfus, and Randy Quaid.

6. Besides Julia Louis-Dreyfus, the other yuppie neighbor is played by Nicholas Guest.

Nicholas is the brother of actor and director Christopher Guest, who is known for such films as This is Spinal Tap, Waiting For Guffman, Best In Show, and The Princess Bride (he played the evil six-fingered Count Rugen.)

7. Christmas Vacation went straight-to-video in the UK and was never given an original theatrical release.

In the United States, it became the highest grossing entry in the Vacation series, making over $71 million.

8. While it’s called Christmas Vacation, the movie never gets to Christmas.

It ends on Christmas Eve.

9. The movie that Rusty watches on TV is Frank Capra’s perennial Christmas classic It’s a Wonderful Life.

Capra’s grandson, Frank Capra III, served as Christmas Vacation’s second assistant director.

10. The Griswold’s house and street were built and shot on the Warner Bros.’ backlot in Burbank, California.

The house of their yuppie neighbors is the same one used as Murtaugh’s house in Lethal Weapon.

11. Christmas Vacation was Mae Questel’s (she plays Aunt Bethany) final film.

Questel provided the original voices for Betty Boop and Olive Oyl.

12. The scene in which Chevy Chase insults his boss took a lot of planning.

Before shooting, Chase had the crew place cue cards all over the set behind the camera so he could read the long-winded insult without stopping.

13. The studio originally wanted to cut the scene where the cat gets electrocuted.

They were worried about potential complaints of animal cruelty. But after test audiences listed it as the funniest scene in the movie, the filmmakers convinced them to keep it in.

14. The production originally had a trained squirrel for the scene where it wreaks havoc on the house.

Unfortunately, it died the day before the scene was shot. An untrained squirrel was used in the final film.

15. Gene Autry’s “Here Comes Santa Claus” plays during the final police raid.

Actor Randy Quaid, who plays Uncle Eddie, is Autry’s third cousin.