Getting Clojure: 'compute-area' does not compile (page 89)

The top of page 89 states:

and we also got the calculation wrong:

user=> (defn compute-area [diameter]
  #_=> (* PI radius (/ diameter 2.0)))

The code above does not compile:

Unable to resolve symbol: radius in this context

The intended code is probably something like:

(defn compute-area [diameter]
  (let [radius (/ diameter 2.0)]
    (* PI radius radius)))