When we generate the JavaScript <script> with cl-who we need to put the empty string at the end of the command to have the closing </script> tag like so: (with-html-output-to-string (*standard-output* nil :prologue nil :indent nil) (:html (:head (:title "Temporary page") (:script :language "JavaScript" :src "/test/scripts.js" :type "text/javascript" "")))) It will generate: <html><head><title>Temporary page</title><script language='JavaScript' src='/test/scripts.js' type='text/javascript'></script></head></html> Now if we parse the html with html-parse:parse-html command and convert it back to the string with tree-to-string (here is the thread<http://common-lisp.net/pipermail/cl-who-devel/2007-November/000109.html>about this command) we'll get the broken <script> tag without the closing </script> It's because html-parse:parse-html will produce ((:HTML (:HEAD (:TITLE "Temporary page") ((:SCRIPT :LANGUAGE "JavaScript" :SRC "/test/scripts.js" :TYPE "text/javascript"))))) Note, that there is no "" at the end of (:script) anymore. My question is where this problem should be fixed at html-parse:parse-html level so that parse-html would insert the "" when it finds the <script> tag, or there is a clean way to do it in cl-who?