diff --git a/lib/utils/templatize.html b/lib/utils/templatize.html
index 319ea1a78e..0430f3c0dd 100644
--- a/lib/utils/templatize.html
+++ b/lib/utils/templatize.html
@@ -176,7 +176,7 @@
             } else if (n.localName === 'slot') {
               if (hide) {
                 n.__polymerParent__ = n.parentNode;
-                n.__polymerReplaced__ = new Comment('hidden-slot');
+                n.__polymerReplaced__ = document.createComment('hidden-slot');
                 n.parentNode.replaceChild(n.__polymerReplaced__, n);
               } else {
                 const parent = n.__polymerParent__;