diff --git a/CHANGELOG.md b/CHANGELOG.md
index e00a601..0f8317c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 # CHANGELOG
 
+## 3.3.1
+- fix export dart core libraries
+
 ## 3.3.0
 - feat can disable printing generated code `disclaimer`
 - feat added the `comments` field to the `indexes` to be able to add the comments or copyright to the library
diff --git a/lib/src/dart_code/dart_export.dart b/lib/src/dart_code/dart_export.dart
index a3aaa24..d9974c8 100644
--- a/lib/src/dart_code/dart_export.dart
+++ b/lib/src/dart_code/dart_export.dart
@@ -13,12 +13,16 @@ class DartExport {
     sb ??= StringBuffer();
 
     sb.write('export \'');
-    if (package.endsWith('.dart')) {
-      sb.write(package);
-    } else {
+
+    final segments = package.split(':');
+    if (segments.length > 2) {
+      throw 'Invalid package name: \'$package\'';
+    } else if (segments.length == 1) {
       // TODO: Remove support on 4.0.0 version
       print('[WARNING]: Please change from \'$package\' to \'package:$package.dart\'');
       sb.write('package:$package.dart');
+    } else {
+      sb.write(package);
     }
     sb.write('\'');
 
diff --git a/pubspec.yaml b/pubspec.yaml
index a621ad0..0c31094 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,6 +1,6 @@
 name: index_generator
 description: Automatically generate index / barrel / library files with all the export needed for your library.
-version: 3.3.0
+version: 3.3.1
 homepage: https://github.com/BreX900/index_generator
 
 # dart pub publish --dry-run
@@ -17,7 +17,7 @@ dependencies:
   yaml: ^3.1.1
   checked_yaml: ^2.0.1
   mek_data_class: ^0.1.0
-  json_annotation: ^4.5.0
+  json_annotation: ^4.6.0
   glob: ^2.1.0
 
   pubspec: ^2.2.0
@@ -31,9 +31,9 @@ dev_dependencies:
   # To generate .g files:
   # dart run build_runner build --delete-conflicting-outputs
   # dart run build_runner watch --delete-conflicting-outputs
-  build_runner: ^2.1.11
-  mek_data_class_generator: ^0.1.3
-  json_serializable: ^6.2.0
+  build_runner: ^2.2.0
+  mek_data_class_generator: ^0.1.4
+  json_serializable: ^6.3.1
 
 index_generator:
   exclude:
diff --git a/test/dart_export_test.dart b/test/dart_export_test.dart
index 06a445b..994ff4c 100644
--- a/test/dart_export_test.dart
+++ b/test/dart_export_test.dart
@@ -4,6 +4,16 @@ import 'package:test/scaffolding.dart';
 
 void main() {
   group('test DartExport class', () {
+    test('Export dart package file', () {
+      final export = DartExport(
+        package: 'dart:async',
+        show: ['Future'],
+        hide: ['Stream'],
+      );
+
+      expect(export.toCode(), 'export \'dart:async\' show Future hide Stream;');
+    });
+
     test('Export only library', () {
       final export = DartExport(
         package: 'package:example/example.dart',