diff --git a/lib/sdk/models/base.dart b/lib/sdk/models/base.dart
index d9ae70f..e965b88 100644
--- a/lib/sdk/models/base.dart
+++ b/lib/sdk/models/base.dart
@@ -7,7 +7,9 @@ abstract class BaseModel<T> {
 
   T fromMap(Map<String, dynamic> map);
 
-  T fromJson(String json);
+  T fromJson(String json) {
+    return fromMap(decode(json));
+  }
 
   @override
   String toString() {
diff --git a/lib/sdk/models/category.dart b/lib/sdk/models/category.dart
index e70399a..99bd5cd 100644
--- a/lib/sdk/models/category.dart
+++ b/lib/sdk/models/category.dart
@@ -25,10 +25,5 @@ class Category extends BaseModel<Category> {
     };
   }
 
-  @override
-  Category fromJson(String json) {
-    return fromMap(decode(json));
-  }
-
   static Category fromJsonString(dynamic json) => Category().fromJson(json);
 }
diff --git a/lib/sdk/models/product.dart b/lib/sdk/models/product.dart
index b592e02..e98afb7 100644
--- a/lib/sdk/models/product.dart
+++ b/lib/sdk/models/product.dart
@@ -29,10 +29,5 @@ class Product extends BaseModel<Product> {
     };
   }
 
-  @override
-  Product fromJson(String json) {
-    return fromMap(decode(json));
-  }
-
   static Product fromJsonString(String json) => Product().fromJson(json);
 }