Philosophers have argued that the conceivability of philosophical zom- bies creates problems for physicalism. In response, it has been argued that zombies are not conceivable. Eric Marcus (2004), for example, challenges the conceivability claim. Torin Alter (2007) argues that Marcus’s argument rests on an overly restrictive principle of imagina- tion. I agree that the argument relies on an overly restrictive principle of imagination, but argue that Alter has not put his finger on the right one. In short, Marcus’s argument fails, but not for the reasons Alter gives.