The ongoing war of words between rappers Drake and Meek Mill—over ghostwriter accusations, Nicki Minaj, memes, you name it—has already prompted a bevy of other emcees to weigh in. Rick Ross and Azealia Banks sided with Drake, hip-hop luminaries crowned Drake the victor, and Philly rhymer AR-Ab, a former Meek pal/associate who Drake name-checks in his Meek diss track “Back to Back,” also confessed that Wheelchair Jimmy was rolling over the competition.

Now we can add Mos Def to the mix.

On Friday afternoon, Yasiin Bey posted a YouTube video online issuing an open challenge to battle other emcees, while clowning the Drake vs. Meek Mill beef.

“Me, Black Thought and King Los versus anybody, everybody, battle anybody, I don’t care who you tell,” Mos said. “Red Bull Music Academy put up a mill on that and we’ll give our winnings to charity and take your money too. Tired of these dudes pretending to be dope. You’re alright, but relax, the dope niggas that think they dope, you ain’t as dope as you think.”

He added, “We don’t have to make no back-and-forth corny records about it. We could put it on its feet for the world to see.”

Enter Lupe Fiasco. The 33-year-old Chicago rapper accepted Mos Def’s challenge by posting a meme to his Instagram account, as one does:

If that weren’t enough, he followed it up with a couple bars directed at Mos Def, while also shading Drake for allegedly using a ghostwriter to help with his tracks (Quentin Miller). “If Mos wanna battle, he can get a whiff of the wrath, and I’m behind all these bars don’t need to tap Miller for some genuine drafts…”

If you recall, Meek accused Drake of using Quentin Miller to pen Drake’s guest verse on the Meek track “R.I.C.O.” which, along with Drake not tweeting out Meek’s album, set off the feud. Then, DJ Funkmaster Flex proceeded to leak a series of reference tracks that Miller allegedly penned for Drake.

Miller, however, wrote a mini-essay on his Tumblr saying that he was nothing but a downtrodden dude working at a bakery when Drake plucked him from obscurity, writing, “I am not and never will be a ‘ghostwriter’ for drake.. Im proud to say that we’ve collaborated .. but i could never take credit for anything other than the few songs we worked on together.”