The Hunger Games: Mockingjay -- Part 2" -- even when they're trying to whistle a tune from their own movie.

During the "Mockingjay" at San Diego Comic-Con on Thursday, castmates Liam Hemsworth all tried -- and adorably, hilariously failed -- to replicate the series's iconic Mockingjay whistle tone. But the trio, and the rest of their castmates on the , just could not nail the four-note melody, which was memorably used by Rue and Katniss in the first film, and brought back throughout the rest of the series as a Mockingjay rallying cry of sorts.

In video of the incident Conan O'Brien joked was a frequent sound during his stand-up routines.

Hemsworth comes closest to whistling an actual song, but as X-Files" theme. Still in the science fiction genre, still not quite right.

Check out the hilarious video below, and try not to get too sad when you realize that this is the last "Hunger Games" at Comic-Con ever.

"The Hunger Games: Mockingjay -- Part 2" hits theaters on November 20.

[via: Screen Crush]

Photo credit: Eric Charbonneau/Invision/AP