diff --git a/packages/core/lib/flutter_generator.dart b/packages/core/lib/flutter_generator.dart
index d306e3333..2fb0326ad 100644
--- a/packages/core/lib/flutter_generator.dart
+++ b/packages/core/lib/flutter_generator.dart
@@ -31,7 +31,11 @@ class FlutterGenerator {
     final flutterGen = config.pubspec.flutterGen;
     final output = config.pubspec.flutterGen.output;
     final lineLength = config.pubspec.flutterGen.lineLength;
-    final formatter = DartFormatter(pageWidth: lineLength, lineEnding: '\n');
+    final formatter = DartFormatter(
+      languageVersion: DartFormatter.latestLanguageVersion,
+      pageWidth: lineLength,
+      lineEnding: '\n',
+    );
 
     void defaultWriter(String contents, String path) {
       final file = File(path);
diff --git a/packages/core/pubspec.yaml b/packages/core/pubspec.yaml
index 64fa4b85c..81af5bb6d 100644
--- a/packages/core/pubspec.yaml
+++ b/packages/core/pubspec.yaml
@@ -24,7 +24,7 @@ dependencies:
   json_annotation: ^4.4.0
   glob: ^2.0.0
 
-  dart_style: ^2.2.4
+  dart_style: '>=2.2.4 <4.0.0'
   archive: ^3.4.0
   args: ^2.0.0
   pub_semver: ^2.0.0
diff --git a/packages/core/test/assets_gen_test.dart b/packages/core/test/assets_gen_test.dart
index 79e795fc6..781b8ab66 100644
--- a/packages/core/test/assets_gen_test.dart
+++ b/packages/core/test/assets_gen_test.dart
@@ -59,7 +59,10 @@ void main() {
       final pubspec = File('test_resources/pubspec_assets_no_list.yaml');
       final config = loadPubspecConfig(pubspec);
       final formatter = DartFormatter(
-          pageWidth: config.pubspec.flutterGen.lineLength, lineEnding: '\n');
+        languageVersion: DartFormatter.latestLanguageVersion,
+        pageWidth: config.pubspec.flutterGen.lineLength,
+        lineEnding: '\n',
+      );
 
       expect(() {
         return generateAssets(
diff --git a/packages/core/test/colors_gen_test.dart b/packages/core/test/colors_gen_test.dart
index 9828c9f0f..95fca2d5c 100644
--- a/packages/core/test/colors_gen_test.dart
+++ b/packages/core/test/colors_gen_test.dart
@@ -23,7 +23,10 @@ void main() {
       final pubspec = File('test_resources/pubspec_colors_no_inputs.yaml');
       final config = loadPubspecConfig(pubspec);
       final formatter = DartFormatter(
-          pageWidth: config.pubspec.flutterGen.lineLength, lineEnding: '\n');
+        languageVersion: DartFormatter.latestLanguageVersion,
+        pageWidth: config.pubspec.flutterGen.lineLength,
+        lineEnding: '\n',
+      );
 
       expect(() {
         return generateColors(
@@ -35,7 +38,10 @@ void main() {
       final pubspec = File('test_resources/pubspec_colors_no_inputs_list.yaml');
       final config = loadPubspecConfig(pubspec);
       final formatter = DartFormatter(
-          pageWidth: config.pubspec.flutterGen.lineLength, lineEnding: '\n');
+        languageVersion: DartFormatter.latestLanguageVersion,
+        pageWidth: config.pubspec.flutterGen.lineLength,
+        lineEnding: '\n',
+      );
 
       expect(() {
         return generateColors(
diff --git a/packages/core/test/fonts_gen_test.dart b/packages/core/test/fonts_gen_test.dart
index 64f1e5ccc..90c7f85de 100644
--- a/packages/core/test/fonts_gen_test.dart
+++ b/packages/core/test/fonts_gen_test.dart
@@ -23,7 +23,10 @@ void main() {
         File('test_resources/pubspec_fonts_no_family.yaml'),
       );
       final formatter = DartFormatter(
-          pageWidth: config.pubspec.flutterGen.lineLength, lineEnding: '\n');
+        languageVersion: DartFormatter.latestLanguageVersion,
+        pageWidth: config.pubspec.flutterGen.lineLength,
+        lineEnding: '\n',
+      );
 
       expect(() {
         return generateFonts(FontsGenConfig.fromConfig(config), formatter);
diff --git a/packages/core/test/gen_test_helper.dart b/packages/core/test/gen_test_helper.dart
index 917dd3547..c0927dbe7 100644
--- a/packages/core/test/gen_test_helper.dart
+++ b/packages/core/test/gen_test_helper.dart
@@ -30,6 +30,7 @@ Future<List<String>> runAssetsGen(
 
   final config = loadPubspecConfig(pubspecFile, buildFile: buildFile);
   final formatter = DartFormatter(
+    languageVersion: DartFormatter.latestLanguageVersion,
     pageWidth: config.pubspec.flutterGen.lineLength,
     lineEnding: '\n',
   );
@@ -73,6 +74,7 @@ Future<List<String>> runColorsGen(
   final pubspecFile = File(pubspec);
   final config = loadPubspecConfig(pubspecFile);
   final formatter = DartFormatter(
+    languageVersion: DartFormatter.latestLanguageVersion,
     pageWidth: config.pubspec.flutterGen.lineLength,
     lineEnding: '\n',
   );
@@ -116,6 +118,7 @@ Future<List<String>> runFontsGen(
   final pubspecFile = File(pubspec);
   final config = loadPubspecConfig(pubspecFile);
   final formatter = DartFormatter(
+    languageVersion: DartFormatter.latestLanguageVersion,
     pageWidth: config.pubspec.flutterGen.lineLength,
     lineEnding: '\n',
   );