Using CCL on a Mac (Version 1.10-r16196 (DarwinX8664)), when I try to open a connection specifying a port: (cl-postgres:open-database “database” "user” "pwd" "localhost" :port 5434) the following error is raised: value :PORT is not an integer from 1 to 65535 ((INTEGER 1 65535)) But even if I try to coerce it explicitly, with something like: (cl-postgres:open-database "database" "user" "pwd" "localhost" :port (coerce 5434 '(integer 1 65535))) the same error is raised. Maybe this depends on CCL, since when I write to the REPL: (type-of (coerce 5434 '(integer 1 65535))) the answer is: (INTEGER 0 1152921504606846975) So, may I suggest to change the parameter check to perform an explicit test on the limits? Thank you very much for your attention Renzo Orsini -- "Nota automatica aggiunta dal sistema di posta. Destina il 5 per mille per sostenere con borse di studio gli studenti meritevoli di Ca' Foscari. E' un atto volontario, non costa nulla e non sostituisce l'8 per mille. Scegli Ca' Foscari: codice fiscale 80007720271 Please note that the above message is addressed only to individuals filing Italian income tax returns."