diff --git a/model/source.dart b/model/source.dart
index deffb84f..94b2b4c6 100644
--- a/model/source.dart
+++ b/model/source.dart
@@ -95,7 +95,7 @@ class Source {
       "sourceCodeUrl": sourceCodeUrl,
       "apiUrl": apiUrl,
       "version": version,
-      "itemType": itemType,
+      "itemType": itemType?.index ?? 0,
       "isFullData": isFullData,
       "appMinVerReq": appMinVerReq,
       "additionalParams": additionalParams,