diff --git a/build/browser-header.js b/build/browser-header.js
index e0022b71..eaff5bfc 100644
--- a/build/browser-header.js
+++ b/build/browser-header.js
@@ -1,4 +1,4 @@
-if (typeof(window.less) === 'undefined') { window.less = {}; }
+if (typeof(window.less) === 'undefined' || typeof(window.less.nodeType) !== 'undefined') { window.less = {}; }
 less = window.less;
 tree = window.less.tree = {};
 less.mode = 'browser';