diff --git a/src/views/Settings.vue b/src/views/Settings.vue
index 76327f6..2805811 100644
--- a/src/views/Settings.vue
+++ b/src/views/Settings.vue
@@ -281,7 +281,7 @@ async function downloadAndInstallUpdate() {
       await update.downloadAndInstall((event) => {
         switch (event.event) {
           case 'Started':
-            contentLength = event.data.contentLength;
+            contentLength = event.data.contentLength ?? 0;
             console.log(`Started downloading ${event.data.contentLength} bytes`);
             break;
           case 'Progress':