After some mucking around, I've come up with the following solution: In my source files, after I declare my package, compile/load the appropriate modules but before I declare anything in my package, I added the following code: (defmethod sb-bsd-sockets:socket-make-stream ((socket sb-bsd-sockets:socket) &key input output (element-type 'character) (buffering :full) (external-format :default) timeout