Earlier this month, it was announced that a crossover between The CW's "The Flash" and CBS's "Supergirl" is happening next month. As fans of the superhero shows are counting down the days before the episode airs, Grant Gustin took to his Instagram this week to share a behind-the-scenes photo of the upcoming crossover.

On Thursday, Feb. 11, Gustin posted a photo of him and Melissa Benoist in costume while on the set of the CBS show. He captioned it, "Those two emblems look pretty good together…@melissabenoist." The day before, "The Flash" star also revealed on the photo sharing app that he was on his way to shoot the crossover on the set of the CBS show.

The 26-year-old posted more photos while on the set, and in one photo he joked that his chair on the set of "Supergirl" was fancier than the one that he has on his show. Just like fans of the DC characters, Gustin appeared to be very enthusiastic about the crossover as he captioned another photo, "Jusssst gonna document the whole experience. Not excited at all. #Supergirl."

The crossover episode will air on the March 28 episode of "Supergirl" titled "World's Finest." No other details were revealed about how the two heroes will meet.

"The Flash and Supergirl are teaming up!" said series executive producers Greg Berlanti and Andrew Kreisberg in a statement. "We want to thank Grant Gustin for making the time to come visit (on top of his already immense workload) and all of the folks at CBS, The CW, Warner Bros. and DC for working this out."

Kreisberg is the showrunner of both series and both come from Berlanti Productions, which also produces "Arrow" and "Legends of Tomorrow." Though the shows are on rival networks, CBS Corp. is a part owner of The CW.

"The Flash" airs Tuesdays at 8 p.m. on The CW while "Supergirl" airs Mondays at 8 p.m. on CBS.