diff --git a/static/js/history.js b/static/js/history.js
index 356b293..30aa38f 100644
--- a/static/js/history.js
+++ b/static/js/history.js
@@ -59,10 +59,12 @@
     }
 
     function formatDistance(kilometers) {
+        if (kilometers == null) return '—';
         return `${kilometers.toFixed(kilometers < 1 ? 2 : 1)} km`;
     }
 
     function formatSpeed(kilometersPerHour) {
+        if (kilometersPerHour == null) return '—';
         return `${kilometersPerHour.toFixed(1)} km/h`;
     }