P.S. I Love You sequel is in the works

Get your tissue boxes ready.

More than a decade since its release, tear-jerker P.S. I Love You is finally getting the sequel we've been waiting for.

The 2007 romantic drama, starring Hilary Swank and Gerard Butler, grossed $156 million at the worldwide box office and has maintained a cult status for being up there with one of the saddest romantic films ever made.

Alcon Entertainment has obtained film rights to the book Postscript, which is the follow-up novel to the original of the same name by author Cecelia Ahern.

Alcon, which will co-finance and co-produce the sequel alongside Black Label Media, also produced the first movie.

P.S. I Love You followed widow Holly Kennedy (Swank) discovering a series of letters her late husband Gerry (Butler) had left behind for her, which were all signed off with the words "P.S. I love you".

In Postscript, the story picks up with Holly seven years after her husband's death, and six since she read his final letter which encouraged her to move on.

Holly's sister asks her to come on her podcast to discuss the letters, which then spurs a support group inspired by Gerry's letters, the P.S. I Love You Club.

They want Holly's help with their own parting messages for loved ones after they're gone.

But her association with the group threatens to dredge up pain from her past, which she has finally left behind.

There's no word yet on whether Swank and Butler will return to reprise their roles.

"A deeply emotional project for me, Postscript is the P.S. to my P.S. and while it is a sequel, it is also a story that stands alone about living a purposeful life in the face of illness, grief and loss," author Ahern wrote.

"I hope that new readers and P.S. I Love You fans alike will embrace Holly's new journey."