Hello, The function postmodern:connected-p should fail when its argument is a variable bounded to nil? For instance, here is some code using the package :postmodern : (defun connect-to-database () (when (not (connected-p *database*)) (connect-toplevel *db-name* *db-user* *db-pass* *db-host*))) This code fails because *database* is nil at first. If the function cl-postgress:database-open-p was changed into this: (defun database-open-p (connection) "Returns a boolean indicating whether the given connection is currently connected." (and connection (connection-socket connection) (open-stream-p (connection-socket connection)))) the code above would work as expected.