diff --git a/project_report/static/src/js/graph_renderer.js b/project_report/static/src/js/graph_renderer.js
index 78e1f18..de6c8fa 100755
--- a/project_report/static/src/js/graph_renderer.js
+++ b/project_report/static/src/js/graph_renderer.js
@@ -324,6 +324,32 @@ var MAX_LEGEND_LENGTH = 25 * (1 + config.device.size_class);
             boxColor: boxColor,
         };
     },
+      /**
+     * This function extracts the information from the data points in tooltipModel.dataPoints
+     * (corresponding to datapoints over a given label determined by the mouse position)
+     * that will be displayed in a custom tooltip.
+     *
+     * @private
+     * @param {Object} tooltipModel see chartjs documentation
+     * @return {Object[]}
+     */
+    _getTooltipItems: function (tooltipModel) {
+        var self = this;
+        var data = this.chart.config.data;
+
+        var orderedItems = tooltipModel.dataPoints.sort(function (dPt1, dPt2) {
+            return dPt2.yLabel - dPt1.yLabel;
+        });
+        return orderedItems.reduce(
+            function (acc, item) {
+                if (item.value > 0) {
+                    acc.push(self._getTooltipItemContent(item, data));
+                }
+                return acc;
+            },
+            []
+        );
+    },
 
     _isRedirectionEnabled: function () {
         return !this.disableLinking &&