diff --git a/lib/country_code_picker.dart b/lib/country_code_picker.dart
index 1ba6ded..1d56969 100644
--- a/lib/country_code_picker.dart
+++ b/lib/country_code_picker.dart
@@ -80,6 +80,10 @@ class CountryCodePicker extends StatefulWidget {
   /// [BoxDecoration] for the flag image
   final Decoration? flagDecoration;
 
+  /// An optional argument for inject list of countries
+  /// with customized codes.
+  final List<Map<String, dynamic>> countryList;
+
   CountryCodePicker({
     this.onChanged,
     this.onInit,
@@ -113,12 +117,13 @@ class CountryCodePicker extends StatefulWidget {
     this.dialogSize,
     this.dialogBackgroundColor,
     this.closeIcon = const Icon(Icons.close),
+    this.countryList = codes,
     Key? key,
   }) : super(key: key);
 
   @override
   State<StatefulWidget> createState() {
-    List<Map> jsonList = codes;
+    List<Map> jsonList = countryList;
 
     List<CountryCode> elements = jsonList
         .map((json) => CountryCode.fromJson(json as Map<String, dynamic>))
diff --git a/lib/country_codes.dart b/lib/country_codes.dart
index 993be09..ab11e3e 100644
--- a/lib/country_codes.dart
+++ b/lib/country_codes.dart
@@ -1,4 +1,4 @@
-List<Map<String, String>> codes = [
+const List<Map<String, String>> codes = [
   {
     "name": "افغانستان",
     "code": "AF",