diff --git a/CLAUDE.md b/CLAUDE.md
index aa7c5a4..56eabdf 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -21,3 +21,16 @@ flutter build apk --release
 # 2. Install (in-place upgrade, preserves config)
 adb install -r build/app/outputs/flutter-apk/app-release.apk
 ```
+
+## Flutter Test Rules
+
+Before running `flutter test`, temporarily remove proxy environment variables for the current shell. The Flutter tester uses a localhost WebSocket, and proxy settings can break that connection with `Invalid WebSocket upgrade request`.
+
+### PowerShell
+
+```powershell
+$env:HTTP_PROXY=''
+$env:HTTPS_PROXY=''
+$env:NO_PROXY='localhost,127.0.0.1,::1'
+flutter test
+```