diff --git a/charts.html b/charts.html
index 039e186..355f214 100644
--- a/charts.html
+++ b/charts.html
@@ -129,7 +129,7 @@
         setInterval(async () => {
             const newDatum = await fetch("/" + ROOT_URL + "data/last/");
             const snapshot = (await newDatum.json()).snapshots[0];
-            const latestTime = chart.data.datasets[0].data[chart.data.datasets[0].data - 1].x;
+            const latestTime = chart.data.datasets[0].data[chart.data.datasets[0].data.length - 1].x;
             if (snapshot.time !== latestTime) {
                 removeExpiredData(chart, snapshot.time);
                 insertSnapshot(chart, snapshot);