diff --git a/DEVELOPER.md b/DEVELOPER.md
index 0740999..6ada674 100644
--- a/DEVELOPER.md
+++ b/DEVELOPER.md
@@ -806,7 +806,7 @@ The app uses a **clean, release-triggered workflow** that rebuilds from scratch
 | Tool | Install | Notes |
 |------|---------|-------|
 | **Homebrew** | [brew.sh](https://brew.sh) | Package manager for macOS |
-| **Flutter SDK** | `brew install --cask flutter` | Installs Flutter + Dart |
+| **Flutter SDK 3.35+** | `brew install --cask flutter` | Installs Flutter + Dart (3.35+ required for RadioGroup widget) |
 | **Xcode** | Mac App Store | Required for iOS builds |
 | **CocoaPods** | `brew install cocoapods` | Required for iOS plugin resolution |
 | **Android SDK** | See below | Required for Android builds |
diff --git a/pubspec.yaml b/pubspec.yaml
index 1a50411..5e05501 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -4,7 +4,7 @@ publish_to: "none"
 version: 2.6.4+47   # The thing after the + is the version code, incremented with each release
 
 environment:
-  sdk: ">=3.5.0 <4.0.0"   # oauth2_client 4.x needs Dart 3.5+
+  sdk: ">=3.8.0 <4.0.0"   # RadioGroup widget requires Dart 3.8+ (Flutter 3.35+)
 
 dependencies:
   flutter: