diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 5ebe99a7b..34dd10a8e 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -30,7 +30,7 @@ jobs:
       - uses: subosito/flutter-action@v2.8.0
         with:
           cache: true
-          flutter-version: ${{ matrix.sdk == 'min' && '2.8.0' || '' }}
+          flutter-version: ${{ matrix.sdk == 'min' && '3.10.0' || '' }}
           channel: ${{ matrix.sdk == 'min' && '' || matrix.channel }}
       - run: |
           chmod +x ./scripts/prepare_pinning_certs.sh
diff --git a/dio/CHANGELOG.md b/dio/CHANGELOG.md
index 2d302bd1f..56d561bb0 100644
--- a/dio/CHANGELOG.md
+++ b/dio/CHANGELOG.md
@@ -5,7 +5,7 @@ See the [Migration Guide][] for the complete breaking changes list.**
 
 ## Unreleased 6.0.0
 
-- The minimum supported Dart version has been bumped from `2.15.0` to `2.19.0`.
+- The minimum supported Dart version has been bumped from `2.15.0` to `3.0.0`.
 - Remove `DefaultHttpClientAdapter` which was deprecated in `5.0.0`.
 - Remove `IOHttpClientAdapter.onHttpClientCreate` which was deprecated in `5.2.0`.
 - Remove `DioError` and `DioErrorType` which was deprecated in `5.2.0`.
diff --git a/dio/pubspec.yaml b/dio/pubspec.yaml
index 8733c211f..7997668b4 100644
--- a/dio/pubspec.yaml
+++ b/dio/pubspec.yaml
@@ -17,7 +17,7 @@ repository: https://github.com/cfug/dio/blob/main/dio
 issue_tracker: https://github.com/cfug/dio/issues
 
 environment:
-  sdk: '>=2.19.0 <4.0.0'
+  sdk: '>=3.0.0 <4.0.0'
 
 dependencies:
   async: ^2.8.2
diff --git a/example/lib/extend_dio.dart b/example/lib/extend_dio.dart
index 7cfe2147a..156670cc1 100644
--- a/example/lib/extend_dio.dart
+++ b/example/lib/extend_dio.dart
@@ -2,7 +2,7 @@ import 'package:dio/dio.dart';
 import 'package:dio/io.dart';
 
 class HttpService extends Dio {
-  HttpService([BaseOptions? baseOptions]) : super(baseOptions) {
+  HttpService([super.baseOptions]) {
     options
       ..baseUrl = 'https://httpbin.org/'
       ..contentType = Headers.jsonContentType;
diff --git a/example/pubspec.yaml b/example/pubspec.yaml
index c5c865dc4..3444ece29 100644
--- a/example/pubspec.yaml
+++ b/example/pubspec.yaml
@@ -4,7 +4,7 @@ version: 0.0.1
 publish_to: "none"
 
 environment:
-  sdk: ">=2.16.0 <3.0.0"
+  sdk: ">=3.0.0 <4.0.0"
 
 dependencies:
   cookie_jar:
diff --git a/example_flutter_app/pubspec.yaml b/example_flutter_app/pubspec.yaml
index 07b0b5035..048b56a0c 100644
--- a/example_flutter_app/pubspec.yaml
+++ b/example_flutter_app/pubspec.yaml
@@ -18,7 +18,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 version: 1.0.0+1
 
 environment:
-  sdk: ">=2.19.0 <4.0.0"
+  sdk: ">=3.0.0 <4.0.0"
 
 dependencies:
   flutter:
diff --git a/plugins/cookie_manager/pubspec.yaml b/plugins/cookie_manager/pubspec.yaml
index 0a0bd3d27..7677e96d8 100644
--- a/plugins/cookie_manager/pubspec.yaml
+++ b/plugins/cookie_manager/pubspec.yaml
@@ -13,11 +13,11 @@ repository: https://github.com/cfug/dio/blob/main/plugins/cookie_manager
 issue_tracker: https://github.com/cfug/dio/issues
 
 environment:
-  sdk: ">=2.19.0 <3.0.0"
+  sdk: ">=3.0.0 <4.0.0"
 
 dependencies:
   cookie_jar: ^4.0.0
-  dio: ^5.2.0
+  dio: ^6.0.0
 
 dev_dependencies:
   lints: any
diff --git a/plugins/http2_adapter/pubspec.yaml b/plugins/http2_adapter/pubspec.yaml
index 0519bd9a3..e61531b5f 100644
--- a/plugins/http2_adapter/pubspec.yaml
+++ b/plugins/http2_adapter/pubspec.yaml
@@ -12,11 +12,11 @@ repository: https://github.com/cfug/dio/blob/main/plugins/http2_adapter
 issue_tracker: https://github.com/cfug/dio/issues
 
 environment:
-  sdk: ">=2.19.0 <3.0.0"
+  sdk: ">=3.0.0 <4.0.0"
 
 dependencies:
   http2: ^2.0.0
-  dio: ^5.2.0
+  dio: ^6.0.0
 
 dev_dependencies:
   crypto: ^3.0.2
diff --git a/plugins/native_dio_adapter/pubspec.yaml b/plugins/native_dio_adapter/pubspec.yaml
index ebff7cd17..ff9086b34 100644
--- a/plugins/native_dio_adapter/pubspec.yaml
+++ b/plugins/native_dio_adapter/pubspec.yaml
@@ -20,7 +20,7 @@ dependencies:
   flutter:
     sdk: flutter
 
-  dio: ^5.4.0
+  dio: ^6.0.0
   cupertino_http: ^1.0.0
   cronet_http: ^0.4.0
   http: ^1.0.0
diff --git a/pubspec.yaml b/pubspec.yaml
index b3184f3db..bfc290523 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -3,7 +3,7 @@ publish_to: 'none'
 repository: https://github.com/cfug/dio
 
 environment:
-  sdk: '>=2.15.0 <4.0.0'
+  sdk: '>=3.0.0 <4.0.0'
 
 dev_dependencies:
   lints: any