Crude type checking?

typecheck.clj

(defn
  ^{:types [Integer Integer Integer]}
  add
  [x y]
  (+ x y))

(defn
  ^{:types [Integer Integer Integer]}
  mult
  [x y]
  (* x y))

(defn typecheck*
  [code]
  (let [types (-> code first meta :types)
	f-type (first types)
	expected-arg-types (rest types)
	actual-arg-types (map type (rest code))]
    (when (some false? (map #(isa? %1 %2) actual-arg-types expected-arg-types))
      (throw (Exception. "Type error")))))