diff --git a/src/content/sync.js b/src/content/sync.js
index 4e1f975..67896da 100644
--- a/src/content/sync.js
+++ b/src/content/sync.js
@@ -63,7 +63,7 @@ export class Sync {
 
   static hasOldData(obj) {
     // FP v3 OR FP v7
-    return Object.hasOwn(obj, 'settings') || Object.values(obj).some(i => i.address);
+    return Object.hasOwn(obj, 'settings') || Object.values(obj).some(i => Object.hasOwn(i, 'address'));
   }
 
   static async getSync(pref) {