diff --git a/example/bin/main_json_serializable.dart b/example/bin/main_json_serializable.dart
index eb7fccfc..0d09e8f8 100644
--- a/example/bin/main_json_serializable.dart
+++ b/example/bin/main_json_serializable.dart
@@ -60,12 +60,12 @@ Future<Request> authHeader(Request request) async => applyHeader(
       "42",
     );
 
-typedef T JsonFactory<T>(Map<String, dynamic> json);
+typedef JsonFactory<T> = T Function(Map<String, dynamic> json);
 
 class JsonSerializableConverter extends JsonConverter {
   final Map<Type, JsonFactory> factories;
 
-  JsonSerializableConverter(this.factories);
+  const JsonSerializableConverter(this.factories);
 
   T? _decodeMap<T>(Map<String, dynamic> values) {
     /// Get jsonFactory using Type parameters
@@ -82,10 +82,10 @@ class JsonSerializableConverter extends JsonConverter {
   List<T> _decodeList<T>(Iterable values) =>
       values.where((v) => v != null).map<T>((v) => _decode<T>(v)).toList();
 
-  dynamic _decode<T>(dynamic entity) {
-    if (entity is Iterable) return _decodeList<T>(entity);
+  dynamic _decode<T>(entity) {
+    if (entity is Iterable) return _decodeList<T>(entity as List);
 
-    if (entity is Map<String, dynamic>) return _decodeMap<T>(entity);
+    if (entity is Map) return _decodeMap<T>(entity as Map<String, dynamic>);
 
     return entity;
   }