If there’s one person who knows the Joker better than anyone else, it’s Mark Hamill. The actor has been voicing the Clown Prince of Crime in numerous adaptations of the Batman franchise for the past twenty-something years. To get his stamp of approval really means something, then, so Gotham‘s Cameron Monaghan should be quite proud, as Hamill has taken to Twitter today to praise his performance as proto-Joker Jerome Valeska.

In response to a Tweet by Monaghan in which he shared a preview of the upcoming second half of Gotham season 4, Hamill revealed himself to be one of the many Bat-fans enjoying Fox’s Dark Knight prequel series, saying: Can’t wait! @cameronmonaghan is KILLING IT as #TheJoker & that’s NO JOKE.

It’s interesting that Hamill describes Monaghan as playing the Joker on Gotham. While his manic ways and recent facial scars look to be heavily hinting that Jerome is a young version of Batman’s nemesis, the show has yet to confirm that outright. In fact, the cast and crew have gone out of their way to argue that Jerome is definitely NOT the Joker. Not to mention that quite recently, David Mazouz clearly stated he’s a separate character.

Fans have mostly reacted negatively to this idea, as Monaghan has been embraced by Joker lovers as an actor worthy of playing the most iconic supervillain ever. What’s more, the idea that the real Joker stole his act from this other clownish killer would be a bit of an insult to him. Thankfully, there’s a compelling fan theory that suggests the Joker could be a kind of alternate personality of Jerome’s, which would technically make them different characters.

The truth will (hopefully) be revealed when Gotham season 4 returns to Fox, starting with episode 12, “Pieces of a Broken Mirror,” airing March 1st.