diff --git a/src/simple-stats.js b/src/simple-stats.js
index f631b2a4..f7114bdc 100644
--- a/src/simple-stats.js
+++ b/src/simple-stats.js
@@ -19,7 +19,7 @@ export function SimpleStats(flightLog) {
 
   const getMinMaxMean = (fieldName) => {
     const index = _.findIndex(fields, (f) => f === fieldName);
-    if (index === -1 || !frames.length || !(index in frames[0])) {
+    if (index === -1 || !frames.length || !(index in frames[0]) || !frames[index][index]) {
       return undefined;
     }
     const result = _.mapValues({