diff --git a/highcharts_excentis/highcharts/highcharts.py b/highcharts_excentis/highcharts/highcharts.py
index 3084568..98923fa 100644
--- a/highcharts_excentis/highcharts/highcharts.py
+++ b/highcharts_excentis/highcharts/highcharts.py
@@ -339,7 +339,7 @@ def buildhtmlheader(self):
         """generate HTML header content"""
         
         if self.drilldown_flag:
-            self.add_JSsource('http://code.highcharts.com/modules/drilldown.js')
+            self.add_JSsource('http://code.highcharts.com/6/modules/drilldown.js')