Clojurians Log v2

Is it intentional that spec-tools' string-transformer does not coerce integer to double ?

(s/def ::iam-double double?)
(st/coerce ::iam-double 500 st/string-transformer) ;; 500  -- still integer
(st/coerce ::iam-double "500" st/string-transformer) ;; 500.0 -- string to double