diff --git a/DEPS b/DEPS
index c8951bd..208ee7a 100644
--- a/DEPS
+++ b/DEPS
@@ -112,7 +112,7 @@
   "pedantic_tag": "v1.5.0",
   "ply_rev": "604b32590ffad5cbb82e4afef1d305512d06ae93",
   "pool_tag": "1.3.6",
-  "protobuf_rev": "0c77167b16d00b561a6055bfe26690af7f26ae88",
+  "protobuf_rev": "7d34c9e4e552a4f66acce32e4344ae27756a1949",
   "pub_rev": "8c363fe26f059c3063f1129adbb3c4e22a8ce954",
   "pub_semver_tag": "1.4.2",
   "quiver-dart_tag": "2.0.0+1",
diff --git a/pkg/vm/test/transformations/protobuf_aware_treeshaker/treeshaker_test.dart b/pkg/vm/test/transformations/protobuf_aware_treeshaker/treeshaker_test.dart
index 66d662e..ec3e99d 100644
--- a/pkg/vm/test/transformations/protobuf_aware_treeshaker/treeshaker_test.dart
+++ b/pkg/vm/test/transformations/protobuf_aware_treeshaker/treeshaker_test.dart
@@ -52,7 +52,7 @@
 
     ProcessResult result =
         Process.runSync(Platform.resolvedExecutable, [file.path]);
-    expect(result.exitCode, 0);
+    expect(result.exitCode, 0, reason: '${result.stderr}\n${result.stdout}');
   } finally {
     if (file.existsSync()) {
       file.deleteSync();
diff --git a/pkg/vm/testcases/transformations/protobuf_aware_treeshaker/lib/freeze_test.dart b/pkg/vm/testcases/transformations/protobuf_aware_treeshaker/lib/freeze_test.dart
new file mode 100644
index 0000000..0529e4a
--- /dev/null
+++ b/pkg/vm/testcases/transformations/protobuf_aware_treeshaker/lib/freeze_test.dart
@@ -0,0 +1,23 @@
+// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:test/test.dart';
+
+import 'generated/foo.pb.dart';
+
+main() {
+  FooKeep foo = FooKeep()
+    ..barKeep = (BarKeep()..aKeep = 5)
+    ..mapKeep['foo'] = (BarKeep()..aKeep = 2)
+    ..aKeep = 43;
+  test('Freezing a message works', () {
+    foo.freeze();
+    expect(foo.barKeep.aKeep, 5);
+    expect(foo.mapKeep['foo'].aKeep, 2);
+    expect(foo.hasHasKeep(), false);
+    expect(foo.aKeep, 43);
+    expect(() => foo.clearClearKeep(),
+        throwsA(const TypeMatcher<UnsupportedError>()));
+  });
+}