The hit 1970s rockers reformed for a tour in 2009 but prior commitments forced vocalist Stewart to miss the comeback and his former bandmates drafted in former Simply Red frontman Mick Hucknall to sing instead.
Rumours suggesting Stewart will eventually rejoin the Stay With Me hitmakers have swirled ever since, and now he has confirmed he is happy to be a part of the reunion, as long as guitarist Wood swears to keep away from his other band in the meantime.
Stewart also wants the musicians play their songs in a different key so he doesn't have to strain his voice.
He tells Mojo magazine, "I can't sing up there any more so they'd have to drop the keys, and they can. They just get lazy. And Ronnie would have to sit there and swear to me the Stones were finished and no longer doing any business, that's it, all over."