diff --git a/pkg/frontend_server/lib/frontend_server.dart b/pkg/frontend_server/lib/frontend_server.dart
index 10eab7b..176909e 100644
--- a/pkg/frontend_server/lib/frontend_server.dart
+++ b/pkg/frontend_server/lib/frontend_server.dart
@@ -53,8 +53,6 @@
   ..addFlag('aot',
       help: 'Run compiler in AOT mode (enables whole-program transformations)',
       defaultsTo: false)
-// TODO(alexmarkov): Cleanup uses in Flutter and remove these obsolete flags.
-  ..addFlag('strong', help: 'Obsolete', defaultsTo: true)
   ..addFlag('tfa',
       help:
           'Enable global type flow analysis and related transformations in AOT mode.',