Justin Theroux is mourning the death of his dog, Dolly.

The 47-year-old actor took to Instagram on Monday to announce his pet's passing.

"Tonight, at sunset, after a heroic struggle...our most loyal family member and protector, Dolly A. laid down her sword and shield," he wrote alongside a few snapshots of his four-legged friend. "She was surrounded by her entire family."

Quoting a few words from George Graham Vest, Theroux then wrote, "The one that never deserts, the one that never proves ungrateful... is the dog— faithful and true, even in death." He ended his post by writing "Rest in Peace Dolly" along with the hashtags #AdoptDontShop and #RescueDog."

The photos also showed the white shepherd being covered in flower petals and wrapped in a blanket. A woman's hands could be spotted in a few of the photos. Some wondered if these hands belonged to Jennifer Aniston.

Theroux shared Dolly with his now-ex. In fact, the Friends actress actually named the beloved pet after Dolly Parton.