diff --git a/Readability.js b/Readability.js
index b2f0792..72fd577 100644
--- a/Readability.js
+++ b/Readability.js
@@ -51,7 +51,7 @@ var Readability = function(uri, doc) {
       if (e.nodeType == e.TEXT_NODE) {
         return rv + '("' + e.textContent + '")';
       }
-      var classDesc = e.className && ("." + Array.prototype.join.call(e.classList, "."));
+      var classDesc = e.className && ("." + e.className.replace(/ /g, "."));
       var elDesc = e.id ? "(#" + e.id + classDesc + ")" :
                           (classDesc ? "(" + classDesc + ")" : "");
       return rv + elDesc;