Better test for the className being an actual string

1 files changed, 1 insertions, 1 deletions

diff --git a/js/piwik.js b/js/piwik.js
index 793cb1af2e..449b1ed7c6 100644
--- a/js/piwik.js
+++ b/js/piwik.js
@@ -1387,7 +1387,7 @@ if (typeof Piwik !== 'object') {
             hasNodeCssClass: function (node, className)
             {
                 if (node && className && className in node && node.className) {
-                    var classes = node.className.split(' ');
+                    var classes = typeof node.className === "string" ? node.className.split(' ') : [];
                     if (-1 !== indexOfArray(classes, className)) {
                         return true;
                     }