diff --git a/fhem/www/pgm2/fhemweb.js b/fhem/www/pgm2/fhemweb.js
index 3baff83d0..24bce4f18 100644
--- a/fhem/www/pgm2/fhemweb.js
+++ b/fhem/www/pgm2/fhemweb.js
@@ -346,7 +346,8 @@ scriptAttribute(sname)
 {
   var attr="";
   $("head script").each(function(){
-    if($(this).attr("src").indexOf(sname) >= 0)
+    var attr = $(this).attr("src");
+    if(attr && attr.indexOf(sname) >= 0)
       attr = $(this).attr("attr");
   });