diff --git a/DEPS b/DEPS
index 2653ba936982..3d3f64b9e4f6 100644
--- a/DEPS
+++ b/DEPS
@@ -120,7 +120,7 @@ vars = {
   # EOL comment after a dependency to disable this and pin it at its current
   # revision.
 
-  "args_rev": "e623652744c82533829f2e62b1aba1a6cf06e291", #
+  "args_rev": "09c0fca1785c9df39288a48f767994eed80bed40", #
   "async_rev": "5f70a996f673d625e3502597084653686c3e754c",
   "bazel_worker_rev": "aa3cc9e826350b960e0c5a67e6065bcedba8b0ac",
   "benchmark_harness_rev": "44f125ae1d045aa3de09fe88a8dd70cb7352d563",
diff --git a/pkg/dartdev/test/commands/pub_test.dart b/pkg/dartdev/test/commands/pub_test.dart
index 8356282a308f..4cfe94667733 100644
--- a/pkg/dartdev/test/commands/pub_test.dart
+++ b/pkg/dartdev/test/commands/pub_test.dart
@@ -91,6 +91,7 @@ void pub() {
     var result = await p.run(['pub', 'deps', '--foo']);
     expect(result.exitCode, 64);
     expect(result.stdout, isEmpty);
-    expect(result.stderr, startsWith('Could not find an option named "foo".'));
+    expect(
+        result.stderr, startsWith('Could not find an option named "--foo".'));
   });
 }
diff --git a/pkg/dartdev/test/commands/run_test.dart b/pkg/dartdev/test/commands/run_test.dart
index 0c1a58b415c4..6954dec69258 100644
--- a/pkg/dartdev/test/commands/run_test.dart
+++ b/pkg/dartdev/test/commands/run_test.dart
@@ -414,7 +414,7 @@ void main(List<String> args) => print("$b $args");
     expect(result.stdout, isEmpty);
     expect(
       result.stderr,
-      contains('Could not find an option named "vm-name".'),
+      contains('Could not find an option named "--vm-name".'),
     );
     expect(result.exitCode, 64);
   });
@@ -433,7 +433,7 @@ void main(List<String> args) => print("$b $args");
     expect(result.stdout, isEmpty);
     expect(
       result.stderr,
-      contains('Could not find an option named "verbose_gc".'),
+      contains('Could not find an option named "--verbose_gc".'),
     );
     expect(result.exitCode, 64);
   });
diff --git a/pkg/dev_compiler/test/worker/worker_test.dart b/pkg/dev_compiler/test/worker/worker_test.dart
index b6652aac85b6..5e341162495e 100644
--- a/pkg/dev_compiler/test/worker/worker_test.dart
+++ b/pkg/dev_compiler/test/worker/worker_test.dart
@@ -113,7 +113,7 @@ void main() {
 
       expect(result.exitCode, 64);
       expect(result.stdout,
-          contains('Could not find an option named "does-not-exist"'));
+          contains('Could not find an option named "--does-not-exist"'));
       expect(result.stderr, isEmpty);
       expect(outputJsFile.existsSync(), isFalse);
     });
diff --git a/pkg/test_runner/test/options_test.dart b/pkg/test_runner/test/options_test.dart
index c8c1e93df738..204a28417767 100644
--- a/pkg/test_runner/test/options_test.dart
+++ b/pkg/test_runner/test/options_test.dart
@@ -86,16 +86,16 @@ void testValidation() {
       ['--timeout=1,2'], 'Integer value expected for option "--timeout".');
 
   expectValidationError(['--progress=unknown'],
-      '"unknown" is not an allowed value for option "progress".');
+      '"unknown" is not an allowed value for option "--progress".');
   // Don't allow multiple.
   expectValidationError(['--progress=compact,silent'],
-      '"compact,silent" is not an allowed value for option "progress".');
+      '"compact,silent" is not an allowed value for option "--progress".');
 
   expectValidationError(['--nnbd=unknown'],
-      '"unknown" is not an allowed value for option "nnbd".');
+      '"unknown" is not an allowed value for option "--nnbd".');
   // Don't allow multiple.
   expectValidationError(['--nnbd=weak,strong'],
-      '"weak,strong" is not an allowed value for option "nnbd".');
+      '"weak,strong" is not an allowed value for option "--nnbd".');
 
   // Don't allow invalid named configurations.
   expectValidationError(['-ninvalid-vm-android-simarm'],