diff --git a/example/lib/main.dart b/example/lib/main.dart
index 56fee62..27eaf16 100644
--- a/example/lib/main.dart
+++ b/example/lib/main.dart
@@ -13,8 +13,8 @@ class MyApp extends StatelessWidget {
       title: 'Sample',
       theme: ThemeData(
         disabledColor: Colors.purple,
-        colorScheme: ColorScheme.fromSwatch(primarySwatch: Colors.indigo)
-            .copyWith(secondary: Colors.blue),
+        colorScheme:
+            ColorScheme.fromSwatch(primarySwatch: Colors.indigo).copyWith(secondary: Colors.blue),
       ),
       home: createScaffold(context),
     );
diff --git a/example/pubspec.lock b/example/pubspec.lock
index 31829a4..5c7f655 100644
--- a/example/pubspec.lock
+++ b/example/pubspec.lock
@@ -1,34 +1,14 @@
 # Generated by pub
 # See https://dart.dev/tools/pub/glossary#lockfile
 packages:
-  async:
-    dependency: transitive
-    description:
-      name: async
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.8.2"
-  boolean_selector:
-    dependency: transitive
-    description:
-      name: boolean_selector
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.1.0"
   characters:
     dependency: transitive
     description:
       name: characters
-      url: "https://pub.dartlang.org"
+      sha256: "04a925763edad70e8443c99234dc3328f442e811f1d8fd1a72f1c8ad0f69a605"
+      url: "https://pub.dev"
     source: hosted
-    version: "1.2.0"
-  charcode:
-    dependency: transitive
-    description:
-      name: charcode
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.3.1"
+    version: "1.3.0"
   checkbox_formfield:
     dependency: "direct main"
     description:
@@ -36,125 +16,55 @@ packages:
       relative: true
     source: path
     version: "0.2.0"
-  clock:
-    dependency: transitive
-    description:
-      name: clock
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.1.0"
   collection:
     dependency: transitive
     description:
       name: collection
-      url: "https://pub.dartlang.org"
+      sha256: ee67cb0715911d28db6bf4af1026078bd6f0128b07a5f66fb2ed94ec6783c09a
+      url: "https://pub.dev"
     source: hosted
-    version: "1.15.0"
+    version: "1.18.0"
   cupertino_icons:
     dependency: "direct main"
     description:
       name: cupertino_icons
-      url: "https://pub.dartlang.org"
+      sha256: "1989d917fbe8e6b39806207df5a3fdd3d816cbd090fac2ce26fb45e9a71476e5"
+      url: "https://pub.dev"
     source: hosted
     version: "1.0.4"
-  fake_async:
-    dependency: transitive
-    description:
-      name: fake_async
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.2.0"
   flutter:
     dependency: "direct main"
     description: flutter
     source: sdk
     version: "0.0.0"
-  flutter_test:
-    dependency: "direct dev"
-    description: flutter
-    source: sdk
-    version: "0.0.0"
-  matcher:
+  material_color_utilities:
     dependency: transitive
     description:
-      name: matcher
-      url: "https://pub.dartlang.org"
+      name: material_color_utilities
+      sha256: "0e0a020085b65b6083975e499759762399b4475f766c21668c4ecca34ea74e5a"
+      url: "https://pub.dev"
     source: hosted
-    version: "0.12.11"
+    version: "0.8.0"
   meta:
     dependency: transitive
     description:
       name: meta
-      url: "https://pub.dartlang.org"
+      sha256: "7687075e408b093f36e6bbf6c91878cc0d4cd10f409506f7bc996f68220b9136"
+      url: "https://pub.dev"
     source: hosted
-    version: "1.7.0"
-  path:
-    dependency: transitive
-    description:
-      name: path
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.8.0"
+    version: "1.12.0"
   sky_engine:
     dependency: transitive
     description: flutter
     source: sdk
     version: "0.0.99"
-  source_span:
-    dependency: transitive
-    description:
-      name: source_span
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.8.1"
-  stack_trace:
-    dependency: transitive
-    description:
-      name: stack_trace
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.10.0"
-  stream_channel:
-    dependency: transitive
-    description:
-      name: stream_channel
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.1.0"
-  string_scanner:
-    dependency: transitive
-    description:
-      name: string_scanner
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.1.0"
-  term_glyph:
-    dependency: transitive
-    description:
-      name: term_glyph
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.2.0"
-  test_api:
-    dependency: transitive
-    description:
-      name: test_api
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.4.3"
-  typed_data:
-    dependency: transitive
-    description:
-      name: typed_data
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.3.0"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
-      url: "https://pub.dartlang.org"
+      sha256: "80b3257d1492ce4d091729e3a67a60407d227c27241d6927be0130c98e741803"
+      url: "https://pub.dev"
     source: hosted
-    version: "2.1.1"
+    version: "2.1.4"
 sdks:
-  dart: ">=2.14.0 <3.0.0"
+  dart: ">=3.3.0-0 <4.0.0"
diff --git a/example/pubspec.yaml b/example/pubspec.yaml
index 899cae1..4bbc00a 100644
--- a/example/pubspec.yaml
+++ b/example/pubspec.yaml
@@ -4,7 +4,7 @@ version: 1.0.0+1
 publish_to: none
 
 environment:
-  sdk: '>=2.12.0 <3.0.0'
+  sdk: ">=3.0.0 <4.0.0"
 
 dependencies:
   flutter:
@@ -16,8 +16,6 @@ dependencies:
     path: ../
 
 dev_dependencies:
-  flutter_test:
-    sdk: flutter
 
 flutter:
-  uses-material-design: true
\ No newline at end of file
+  uses-material-design: true
diff --git a/lib/checkbox_list_tile_formfield.dart b/lib/checkbox_list_tile_formfield.dart
index 56afec1..c19dfc7 100644
--- a/lib/checkbox_list_tile_formfield.dart
+++ b/lib/checkbox_list_tile_formfield.dart
@@ -27,8 +27,7 @@ class CheckboxListTileFormField extends FormField<bool> {
           initialValue: initialValue,
           autovalidateMode: autovalidateMode,
           builder: (FormFieldState<bool> state) {
-            errorColor ??=
-                (context == null ? Colors.red : Theme.of(context).errorColor);
+            errorColor ??= (context == null ? Colors.red : Theme.of(context).colorScheme.error);
 
             return CheckboxListTile(
               title: title,
diff --git a/pubspec.lock b/pubspec.lock
index 03307d6..5ce75fe 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -1,146 +1,55 @@
 # Generated by pub
 # See https://dart.dev/tools/pub/glossary#lockfile
 packages:
-  async:
-    dependency: transitive
-    description:
-      name: async
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.8.2"
-  boolean_selector:
-    dependency: transitive
-    description:
-      name: boolean_selector
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.1.0"
   characters:
     dependency: transitive
     description:
       name: characters
-      url: "https://pub.dartlang.org"
+      sha256: "04a925763edad70e8443c99234dc3328f442e811f1d8fd1a72f1c8ad0f69a605"
+      url: "https://pub.dev"
     source: hosted
-    version: "1.2.0"
-  charcode:
-    dependency: transitive
-    description:
-      name: charcode
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.3.1"
-  clock:
-    dependency: transitive
-    description:
-      name: clock
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.1.0"
+    version: "1.3.0"
   collection:
     dependency: transitive
     description:
       name: collection
-      url: "https://pub.dartlang.org"
+      sha256: ee67cb0715911d28db6bf4af1026078bd6f0128b07a5f66fb2ed94ec6783c09a
+      url: "https://pub.dev"
     source: hosted
-    version: "1.15.0"
-  fake_async:
-    dependency: transitive
-    description:
-      name: fake_async
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.2.0"
+    version: "1.18.0"
   flutter:
     dependency: "direct main"
     description: flutter
     source: sdk
     version: "0.0.0"
-  flutter_test:
-    dependency: "direct dev"
-    description: flutter
-    source: sdk
-    version: "0.0.0"
-  matcher:
+  material_color_utilities:
     dependency: transitive
     description:
-      name: matcher
-      url: "https://pub.dartlang.org"
+      name: material_color_utilities
+      sha256: "0e0a020085b65b6083975e499759762399b4475f766c21668c4ecca34ea74e5a"
+      url: "https://pub.dev"
     source: hosted
-    version: "0.12.11"
+    version: "0.8.0"
   meta:
     dependency: transitive
     description:
       name: meta
-      url: "https://pub.dartlang.org"
+      sha256: "7687075e408b093f36e6bbf6c91878cc0d4cd10f409506f7bc996f68220b9136"
+      url: "https://pub.dev"
     source: hosted
-    version: "1.7.0"
-  path:
-    dependency: transitive
-    description:
-      name: path
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.8.0"
+    version: "1.12.0"
   sky_engine:
     dependency: transitive
     description: flutter
     source: sdk
     version: "0.0.99"
-  source_span:
-    dependency: transitive
-    description:
-      name: source_span
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.8.1"
-  stack_trace:
-    dependency: transitive
-    description:
-      name: stack_trace
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.10.0"
-  stream_channel:
-    dependency: transitive
-    description:
-      name: stream_channel
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.1.0"
-  string_scanner:
-    dependency: transitive
-    description:
-      name: string_scanner
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.1.0"
-  term_glyph:
-    dependency: transitive
-    description:
-      name: term_glyph
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.2.0"
-  test_api:
-    dependency: transitive
-    description:
-      name: test_api
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "0.4.3"
-  typed_data:
-    dependency: transitive
-    description:
-      name: typed_data
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.3.0"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
-      url: "https://pub.dartlang.org"
+      sha256: "80b3257d1492ce4d091729e3a67a60407d227c27241d6927be0130c98e741803"
+      url: "https://pub.dev"
     source: hosted
-    version: "2.1.1"
+    version: "2.1.4"
 sdks:
-  dart: ">=2.14.0 <3.0.0"
+  dart: ">=3.3.0-0 <4.0.0"
diff --git a/pubspec.yaml b/pubspec.yaml
index 11aa471..a56b1f0 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,18 +1,16 @@
 name: checkbox_formfield
 description: This package contains checkbox widgets that can be used as FormField for Flutter beginners.
-version: 0.2.0
+version: 0.3.0
 homepage: https://reidha.github.io/
 repository: https://github.com/reidha/checkbox_formfield
 
 environment:
-  sdk: '>=2.12.0 <3.0.0'
+  sdk: ">=3.0.0 <4.0.0"
 
 dependencies:
   flutter:
     sdk: flutter
 
 dev_dependencies:
-  flutter_test:
-    sdk: flutter
 
 flutter: