diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7a0efb606..93485ef68 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+## 0.12.38+3
+
+* Fix Dart 2 runtime errors around communicating with browsers.
+
+
 ## 0.12.38+2
 
 * Fix more Dart 2 runtime type errors.
diff --git a/lib/src/runner/browser/browser_manager.dart b/lib/src/runner/browser/browser_manager.dart
index 7222fc361..4e6d14cb3 100644
--- a/lib/src/runner/browser/browser_manager.dart
+++ b/lib/src/runner/browser/browser_manager.dart
@@ -171,7 +171,7 @@ class BrowserManager {
     // Whenever we get a message, no matter which child channel it's for, we the
     // know browser is still running code which means the user isn't debugging.
     _channel = new MultiChannel(
-        webSocket.transform(jsonDocument).changeStream((stream) {
+        webSocket.cast<String>().transform(jsonDocument).changeStream((stream) {
       return stream.map((message) {
         if (!_closed) _timer.reset();
         for (var controller in _controllers) {
@@ -219,15 +219,15 @@ class BrowserManager {
 
     // The virtual channel will be closed when the suite is closed, in which
     // case we should unload the iframe.
-    var suiteChannel = _channel.virtualChannel();
-    var suiteChannelID = suiteChannel.id;
-    suiteChannel = suiteChannel
+    var virtualChannel = _channel.virtualChannel();
+    var suiteChannelID = virtualChannel.id;
+    var suiteChannel = virtualChannel
         .transformStream(new StreamTransformer.fromHandlers(handleDone: (sink) {
       closeIframe();
       sink.close();
     }));
 
-    return await _pool.withResource<Future<RunnerSuite>>(() async {
+    return await _pool.withResource<RunnerSuite>(() async {
       _channel.sink.add({
         "command": "loadSuite",
         "url": url.toString(),
diff --git a/pubspec.yaml b/pubspec.yaml
index b887bf3f5..4a624927d 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: test
-version: 0.12.38+2
+version: 0.12.38+3
 author: Dart Team <misc@dartlang.org>
 description: A library for writing dart unit tests.
 homepage: https://github.com/dart-lang/test