Custom Head Tags don't save

Trying to put:

<script>
var $buoop = {c:2};
function $buo_f(){
 var e = document.createElement("script");
 e.src = "//browser-update.org/update.min.js";
 document.body.appendChild(e);
};
try {document.addEventListener("DOMContentLoaded", $buo_f,false)}
catch(e){window.attachEvent("onload", $buo_f)}
</script>

into the head section, but even though it appears to save when I hit save, it never appears in the head, and when I return to the custom head tags page the text box where I pasted the code before is empty.