diff --git a/packages/core/lib/generators/generator_helper.dart b/packages/core/lib/generators/generator_helper.dart
index fb95a81f..25109bd3 100644
--- a/packages/core/lib/generators/generator_helper.dart
+++ b/packages/core/lib/generators/generator_helper.dart
@@ -1,5 +1,6 @@
 String get header {
-  return '''/// GENERATED CODE - DO NOT MODIFY BY HAND
+  return '''// @dart = 2.10
+/// GENERATED CODE - DO NOT MODIFY BY HAND
 /// *****************************************************
 ///  FlutterGen
 /// *****************************************************
diff --git a/packages/core/test_resources/actual_data/assets.gen.dart b/packages/core/test_resources/actual_data/assets.gen.dart
index 77d4ef54..c7382b2a 100644
--- a/packages/core/test_resources/actual_data/assets.gen.dart
+++ b/packages/core/test_resources/actual_data/assets.gen.dart
@@ -1,3 +1,4 @@
+// @dart = 2.10
 /// GENERATED CODE - DO NOT MODIFY BY HAND
 /// *****************************************************
 ///  FlutterGen
diff --git a/packages/core/test_resources/actual_data/assets_camel_case.gen.dart b/packages/core/test_resources/actual_data/assets_camel_case.gen.dart
index 2eba7d43..9aae8b9d 100644
--- a/packages/core/test_resources/actual_data/assets_camel_case.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_camel_case.gen.dart
@@ -1,3 +1,4 @@
+// @dart = 2.10
 /// GENERATED CODE - DO NOT MODIFY BY HAND
 /// *****************************************************
 ///  FlutterGen
diff --git a/packages/core/test_resources/actual_data/assets_flare_integrations.gen.dart b/packages/core/test_resources/actual_data/assets_flare_integrations.gen.dart
index deca4fe3..42119bf5 100644
--- a/packages/core/test_resources/actual_data/assets_flare_integrations.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_flare_integrations.gen.dart
@@ -1,3 +1,4 @@
+// @dart = 2.10
 /// GENERATED CODE - DO NOT MODIFY BY HAND
 /// *****************************************************
 ///  FlutterGen
diff --git a/packages/core/test_resources/actual_data/assets_ignore_files.gen.dart b/packages/core/test_resources/actual_data/assets_ignore_files.gen.dart
index 89b4ca50..d3ffcf84 100644
--- a/packages/core/test_resources/actual_data/assets_ignore_files.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_ignore_files.gen.dart
@@ -1,3 +1,4 @@
+// @dart = 2.10
 /// GENERATED CODE - DO NOT MODIFY BY HAND
 /// *****************************************************
 ///  FlutterGen
diff --git a/packages/core/test_resources/actual_data/assets_no_integrations.gen.dart b/packages/core/test_resources/actual_data/assets_no_integrations.gen.dart
index 631f4fb6..59c50858 100644
--- a/packages/core/test_resources/actual_data/assets_no_integrations.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_no_integrations.gen.dart
@@ -1,3 +1,4 @@
+// @dart = 2.10
 /// GENERATED CODE - DO NOT MODIFY BY HAND
 /// *****************************************************
 ///  FlutterGen
diff --git a/packages/core/test_resources/actual_data/assets_snake_case.gen.dart b/packages/core/test_resources/actual_data/assets_snake_case.gen.dart
index 37dc74a6..2e675b8a 100644
--- a/packages/core/test_resources/actual_data/assets_snake_case.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_snake_case.gen.dart
@@ -1,3 +1,4 @@
+// @dart = 2.10
 /// GENERATED CODE - DO NOT MODIFY BY HAND
 /// *****************************************************
 ///  FlutterGen
diff --git a/packages/core/test_resources/actual_data/assets_svg_integrations.gen.dart b/packages/core/test_resources/actual_data/assets_svg_integrations.gen.dart
index 643ab134..242f8ea7 100644
--- a/packages/core/test_resources/actual_data/assets_svg_integrations.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_svg_integrations.gen.dart
@@ -1,3 +1,4 @@
+// @dart = 2.10
 /// GENERATED CODE - DO NOT MODIFY BY HAND
 /// *****************************************************
 ///  FlutterGen
diff --git a/packages/core/test_resources/actual_data/assets_unknown_mime_type.gen.dart b/packages/core/test_resources/actual_data/assets_unknown_mime_type.gen.dart
index 61736151..6c971132 100644
--- a/packages/core/test_resources/actual_data/assets_unknown_mime_type.gen.dart
+++ b/packages/core/test_resources/actual_data/assets_unknown_mime_type.gen.dart
@@ -1,3 +1,4 @@
+// @dart = 2.10
 /// GENERATED CODE - DO NOT MODIFY BY HAND
 /// *****************************************************
 ///  FlutterGen
diff --git a/packages/core/test_resources/actual_data/colors.gen.dart b/packages/core/test_resources/actual_data/colors.gen.dart
index 87752a95..200d53d3 100644
--- a/packages/core/test_resources/actual_data/colors.gen.dart
+++ b/packages/core/test_resources/actual_data/colors.gen.dart
@@ -1,3 +1,4 @@
+// @dart = 2.10
 /// GENERATED CODE - DO NOT MODIFY BY HAND
 /// *****************************************************
 ///  FlutterGen
diff --git a/packages/core/test_resources/actual_data/fonts.gen.dart b/packages/core/test_resources/actual_data/fonts.gen.dart
index ba0421a5..c4a1af0d 100644
--- a/packages/core/test_resources/actual_data/fonts.gen.dart
+++ b/packages/core/test_resources/actual_data/fonts.gen.dart
@@ -1,3 +1,4 @@
+// @dart = 2.10
 /// GENERATED CODE - DO NOT MODIFY BY HAND
 /// *****************************************************
 ///  FlutterGen