diff --git a/lib/preferences.dart b/lib/preferences.dart
index 0c338e1..d86e05d 100644
--- a/lib/preferences.dart
+++ b/lib/preferences.dart
@@ -68,6 +68,7 @@ class Preferences {
         "activity": {
           "type": "<%= activity.type %>"
         },
+        "extras": {},
         "_": "&id=${instance.getString(id)}&lat=<%= latitude %>&lon=<%= longitude %>&timestamp=<%= timestamp %>&"
       }'''.split('\n').map((line) => line.trimLeft()).join(),
     );