Unexpected extra "around" wrapping in midje

midje-output

around: start
around: start
block: start
around: start
around: start
before
around: start
before
fact: start
fact: end
after
around: end
after
around: end
around: end
block: end
around: end
around: end

tests.clj

(def ^:dynamic *state* (atom nil))

(defn frob!
  [a v]
  (reset! a v))

(facts "frob!"
  (println "block: start")
  (against-background
   (around :facts (binding [*state* (atom nil)]
                    (println "around: start")
                    ?form
                    (println "around: end"))))
  (fact "sets things"
    (println "fact: start")
    (against-background
     (before :facts (do (println "before")
                           (frob! *state* 17)))
     (after :facts (println "after")))
    @*state* => 17
    (println "fact: end"))
  (println "block: end"))