diff --git a/shell/testing/observatory/launcher.dart b/shell/testing/observatory/launcher.dart
index 82fdd108f3c74..1e3650abaaa4c 100644
--- a/shell/testing/observatory/launcher.dart
+++ b/shell/testing/observatory/launcher.dart
@@ -42,6 +42,7 @@ class ShellLauncher {
     '--observatory-port=0',
     '--non-interactive',
     '--run-forever',
+    '--disable-service-auth-codes',
   ];
   final String shellExecutablePath;
   final String mainDartPath;