CL-HTTP version 51.1 (mac 1.9.1) will do a full compile of CL-HTTP every time you load it. If this behavior inconveniences you, do the following: 1. Open http:http;mac-sysdcl.lisp 2. Go to the bottom where the system is defined. 3. Change the second form in the system definition from :compile-load-always to :compile-load 4. Save the file and proceed as usual.