diff --git a/CHANGELOG.md b/CHANGELOG.md
index 241ecd4..35cd6f0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,7 @@
 ## 1.0.0
 
+- BREAKING: require flutter 3.27.0 or higher
+- BREAKING: require dart 3.0.0 or higher
 - BREAKING: rename autoFocus to autofocus to match `TextField`'s naming
 - Add missing properties from flutter's `TextField`
   - autofillHints
diff --git a/lib/src/core/controllers/language_tool_controller.dart b/lib/src/core/controllers/language_tool_controller.dart
index 6df04e2..5f94bae 100644
--- a/lib/src/core/controllers/language_tool_controller.dart
+++ b/lib/src/core/controllers/language_tool_controller.dart
@@ -235,8 +235,8 @@ class LanguageToolController extends TextEditingController {
             ),
             mouseCursor: WidgetStateMouseCursor.textable,
             style: style?.copyWith(
-              backgroundColor: mistakeColor.withOpacity(
-                highlightStyle.backgroundOpacity,
+              backgroundColor: mistakeColor.withValues(
+                alpha: highlightStyle.backgroundOpacity,
               ),
               decoration: highlightStyle.decoration,
               decorationColor: mistakeColor,
diff --git a/pubspec.yaml b/pubspec.yaml
index 954cc2d..d475570 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -4,8 +4,8 @@ version: 1.0.0
 homepage: https://github.com/solid-software/languagetool_textfield/
 
 environment:
-  sdk: ">=2.18.6 <4.0.0"
-  flutter: ">=1.17.0"
+  sdk: ">=3.0.0 <4.0.0"
+  flutter: ">=3.27.0"
 
 dependencies:
   async: ^2.11.0