diff --git a/packages/go_router_builder/test_inputs/shell_route_data.dart b/packages/go_router_builder/test_inputs/shell_route_data.dart
index b4839d9..2b6f5bb 100644
--- a/packages/go_router_builder/test_inputs/shell_route_data.dart
+++ b/packages/go_router_builder/test_inputs/shell_route_data.dart
@@ -4,21 +4,15 @@
 
 import 'package:go_router/go_router.dart';
 
-@TypedShellRoute<ShellRouteNoConstConstructor>(
-  routes: <TypedRoute<RouteData>>[],
-)
+@TypedShellRoute<ShellRouteNoConstConstructor>()
 class ShellRouteNoConstConstructor extends ShellRouteData {}
 
-@TypedShellRoute<ShellRouteWithConstConstructor>(
-  routes: <TypedRoute<RouteData>>[],
-)
+@TypedShellRoute<ShellRouteWithConstConstructor>()
 class ShellRouteWithConstConstructor extends ShellRouteData {
   const ShellRouteWithConstConstructor();
 }
 
-@TypedShellRoute<ShellRouteWithRestorationScopeId>(
-  routes: <TypedRoute<RouteData>>[],
-)
+@TypedShellRoute<ShellRouteWithRestorationScopeId>()
 class ShellRouteWithRestorationScopeId extends ShellRouteData {
   const ShellRouteWithRestorationScopeId();
 
diff --git a/packages/go_router_builder/test_inputs/shell_route_data_without_unnamed_constructor.dart b/packages/go_router_builder/test_inputs/shell_route_data_without_unnamed_constructor.dart
index 24e97bf..23ea2a4 100644
--- a/packages/go_router_builder/test_inputs/shell_route_data_without_unnamed_constructor.dart
+++ b/packages/go_router_builder/test_inputs/shell_route_data_without_unnamed_constructor.dart
@@ -4,9 +4,7 @@
 
 import 'package:go_router/go_router.dart';
 
-@TypedShellRoute<ShellRouteWithoutUnnamedConstructor>(
-  routes: <TypedRoute<RouteData>>[],
-)
+@TypedShellRoute<ShellRouteWithoutUnnamedConstructor>()
 class ShellRouteWithoutUnnamedConstructor extends ShellRouteData {
   const ShellRouteWithoutUnnamedConstructor.namedConstructor();
 }
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/CHANGELOG.md b/packages/in_app_purchase/in_app_purchase_storekit/CHANGELOG.md
index f31e13d..c5cfa3b 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/CHANGELOG.md
+++ b/packages/in_app_purchase/in_app_purchase_storekit/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.4.5
+
+* Makes `SKError.userInfo` key non-nullable to comply with json serialization requirements.
+
 ## 0.4.4+1
 
 * Removes code for versions of iOS older than 13.0.
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/enum_converters.dart b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/enum_converters.dart
index 6fb12ee..0c7ad0a 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/enum_converters.dart
+++ b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/enum_converters.dart
@@ -121,6 +121,7 @@
   late SKPaymentTransactionStateWrapper response;
   late SKSubscriptionPeriodUnit unit;
   late SKProductDiscountPaymentMode discountPaymentMode;
+  late SKProductDiscountType discountType;
 }
 
 /// Serializer for [SKProductDiscountType].
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/enum_converters.g.dart b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/enum_converters.g.dart
index a4c3d60..25a4d28 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/enum_converters.g.dart
+++ b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/enum_converters.g.dart
@@ -15,6 +15,10 @@
   ..discountPaymentMode = $enumDecode(
     _$SKProductDiscountPaymentModeEnumMap,
     json['discountPaymentMode'],
+  )
+  ..discountType = $enumDecode(
+    _$SKProductDiscountTypeEnumMap,
+    json['discountType'],
   );
 
 const _$SKPaymentTransactionStateWrapperEnumMap = {
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_payment_queue_wrapper.dart b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_payment_queue_wrapper.dart
index c5ba0f0..054c94d 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_payment_queue_wrapper.dart
+++ b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_payment_queue_wrapper.dart
@@ -378,7 +378,7 @@
   ///
   /// Any key of the map must be a valid [NSErrorUserInfoKey](https://developer.apple.com/documentation/foundation/nserroruserinfokey?language=objc).
   @JsonKey(defaultValue: <String, dynamic>{})
-  final Map<String?, Object?>? userInfo;
+  final Map<String, Object?>? userInfo;
 
   @override
   bool operator ==(Object other) {
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_payment_queue_wrapper.g.dart b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_payment_queue_wrapper.g.dart
index 7dbd5b8..9e8080c 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_payment_queue_wrapper.g.dart
+++ b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_payment_queue_wrapper.g.dart
@@ -7,7 +7,7 @@
 // **************************************************************************
 
 SKError _$SKErrorFromJson(Map json) => SKError(
-  code: json['code'] as int? ?? 0,
+  code: (json['code'] as num?)?.toInt() ?? 0,
   domain: json['domain'] as String? ?? '',
   userInfo:
       (json['userInfo'] as Map?)?.map((k, e) => MapEntry(k as String, e)) ?? {},
@@ -17,9 +17,14 @@
   productIdentifier: json['productIdentifier'] as String? ?? '',
   applicationUsername: json['applicationUsername'] as String?,
   requestData: json['requestData'] as String?,
-  quantity: json['quantity'] as int? ?? 0,
+  quantity: (json['quantity'] as num?)?.toInt() ?? 0,
   simulatesAskToBuyInSandbox:
       json['simulatesAskToBuyInSandbox'] as bool? ?? false,
+  paymentDiscount: json['paymentDiscount'] == null
+      ? null
+      : SKPaymentDiscountWrapper.fromJson(
+          Map<String, dynamic>.from(json['paymentDiscount'] as Map),
+        ),
 );
 
 Map<String, dynamic> _$SKPaymentWrapperToJson(SKPaymentWrapper instance) =>
@@ -29,6 +34,7 @@
       'requestData': instance.requestData,
       'quantity': instance.quantity,
       'simulatesAskToBuyInSandbox': instance.simulatesAskToBuyInSandbox,
+      'paymentDiscount': instance.paymentDiscount,
     };
 
 SKPaymentDiscountWrapper _$SKPaymentDiscountWrapperFromJson(Map json) =>
@@ -37,7 +43,7 @@
       keyIdentifier: json['keyIdentifier'] as String,
       nonce: json['nonce'] as String,
       signature: json['signature'] as String,
-      timestamp: json['timestamp'] as int,
+      timestamp: (json['timestamp'] as num).toInt(),
     );
 
 Map<String, dynamic> _$SKPaymentDiscountWrapperToJson(
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_payment_transaction_wrappers.g.dart b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_payment_transaction_wrappers.g.dart
index 48d8e5b..6aaf956 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_payment_transaction_wrappers.g.dart
+++ b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_payment_transaction_wrappers.g.dart
@@ -12,7 +12,7 @@
         Map<String, dynamic>.from(json['payment'] as Map),
       ),
       transactionState: const SKTransactionStatusConverter().fromJson(
-        json['transactionState'] as int?,
+        (json['transactionState'] as num?)?.toInt(),
       ),
       originalTransaction: json['originalTransaction'] == null
           ? null
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_product_wrapper.dart b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_product_wrapper.dart
index 2b6f8ec..424bb9f 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_product_wrapper.dart
+++ b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_product_wrapper.dart
@@ -384,7 +384,7 @@
   /// A string used to uniquely identify a discount offer for a product.
   ///
   /// You set up offers and their identifiers in App Store Connect.
-  @JsonKey(defaultValue: null)
+  @JsonKey()
   final String? identifier;
 
   /// Values representing the types of discount offers an app can present.
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_product_wrapper.g.dart b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_product_wrapper.g.dart
index 0423d5e..acbfb2d 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_product_wrapper.g.dart
+++ b/packages/in_app_purchase/in_app_purchase_storekit/lib/src/store_kit_wrappers/sk_product_wrapper.g.dart
@@ -27,9 +27,9 @@
 SKProductSubscriptionPeriodWrapper _$SKProductSubscriptionPeriodWrapperFromJson(
   Map json,
 ) => SKProductSubscriptionPeriodWrapper(
-  numberOfUnits: json['numberOfUnits'] as int? ?? 0,
+  numberOfUnits: (json['numberOfUnits'] as num?)?.toInt() ?? 0,
   unit: const SKSubscriptionPeriodUnitConverter().fromJson(
-    json['unit'] as int?,
+    (json['unit'] as num?)?.toInt(),
   ),
 );
 
@@ -39,18 +39,18 @@
       priceLocale: SKPriceLocaleWrapper.fromJson(
         (json['priceLocale'] as Map?)?.map((k, e) => MapEntry(k as String, e)),
       ),
-      numberOfPeriods: json['numberOfPeriods'] as int? ?? 0,
+      numberOfPeriods: (json['numberOfPeriods'] as num?)?.toInt() ?? 0,
       paymentMode: const SKProductDiscountPaymentModeConverter().fromJson(
-        json['paymentMode'] as int?,
+        (json['paymentMode'] as num?)?.toInt(),
       ),
       subscriptionPeriod: SKProductSubscriptionPeriodWrapper.fromJson(
         (json['subscriptionPeriod'] as Map?)?.map(
           (k, e) => MapEntry(k as String, e),
         ),
       ),
-      identifier: json['identifier'] as String? ?? null,
+      identifier: json['identifier'] as String?,
       type: const SKProductDiscountTypeConverter().fromJson(
-        json['type'] as int?,
+        (json['type'] as num?)?.toInt(),
       ),
     );
 
diff --git a/packages/in_app_purchase/in_app_purchase_storekit/pubspec.yaml b/packages/in_app_purchase/in_app_purchase_storekit/pubspec.yaml
index 20bdd5e..83f72e9 100644
--- a/packages/in_app_purchase/in_app_purchase_storekit/pubspec.yaml
+++ b/packages/in_app_purchase/in_app_purchase_storekit/pubspec.yaml
@@ -2,7 +2,7 @@
 description: An implementation for the iOS and macOS platforms of the Flutter `in_app_purchase` plugin. This uses the StoreKit Framework.
 repository: https://github.com/flutter/packages/tree/main/packages/in_app_purchase/in_app_purchase_storekit
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+in_app_purchase%22
-version: 0.4.4+1
+version: 0.4.5
 
 environment:
   sdk: ^3.9.0
@@ -24,7 +24,7 @@
   flutter:
     sdk: flutter
   in_app_purchase_platform_interface: ^1.4.0
-  json_annotation: ^4.3.0
+  json_annotation: ^4.9.0
 
 dev_dependencies:
   build_runner: ^2.0.0