diff --git a/public/app/plugins/panel/graph/graph_tooltip.js b/public/app/plugins/panel/graph/graph_tooltip.js
index 3aec815428f..40ed293ff4e 100644
--- a/public/app/plugins/panel/graph/graph_tooltip.js
+++ b/public/app/plugins/panel/graph/graph_tooltip.js
@@ -195,7 +195,7 @@ function ($) {
           }
 
           var highlightClass = '';
-          if (item && i === item.seriesIndex) {
+          if (item && hoverInfo.index === item.seriesIndex) {
             highlightClass = 'graph-tooltip-list-item--highlight';
           }