diff --git a/client/src/App.js b/client/src/App.js
index 8f216f1..634d0ae 100644
--- a/client/src/App.js
+++ b/client/src/App.js
@@ -719,7 +719,7 @@ function MultiLineChart({title, measurement, dataKey, sensors, colors, end, dura
 			name={title}
 			data={data}
 			lastFormatter={(x) => {
-				const vals = sensors.map(s => x[s]).filter(v => v !== undefined);
+				const vals = sensors.map(s => x[s]).filter(v => v !== undefined && v !== null);
 				return vals.length ? vals[0].toFixed(1) + (units[unitKey] || '') : 'No data';
 			}}
 			loading={loading}