Many original Glee cast members are coming back to film the musical series' 100th episode.

Glee co-creator Ryan Murphy recently tweeted that cast members Amber Riley (who played Mercedes), Mark Salling (Puck), Harry Shum, Jr. (Mike) and Heather Morris (Brittany) are all returning for the show's 100th episode.

Additionally, TVLine recently reported that Dianna Argon (Quinn) wants to return for the episode as well, but is unsure if her schedule will allow for it.

The 100th episode of Glee will feature the cast reuniting to sing some of the show's most iconic songs. Glee fans have been voting for which songs from the show they'd like to hear reinvented for the episode.

Among songs fans can vote on are Don't Stop Believin' by Journey, Somebody to Love by Queen and Keep Holding On by Avril Lavigne.

Glee Christmas Special Song List Revealed 

The episode, which is set to air on Mar. 18, 2014, will feature the senior class at McKinley High looking back on their high school experience and reminiscing while singing iconic Glee songs.

It is currently unknown how Mercedes, Puck, Mike and Brittany will be incorporated back into the show considering they've all graduated from the school, but there will have to a unifying reason, like the death of Finn (the late Cory Monteith) in the season's third episode.

Glee Season 5 Spoilers: Puck Returning for Christmas Special? 

Glee season 5 airs Thursdays at 9 p.m. on Fox. The series will air on Tuesdays at 8 p.m. when it returns in 2014.

Watch a trailer for the next episode of Glee here: