diff --git a/lib/src/runner/browser/post_message_channel.dart b/lib/src/runner/browser/post_message_channel.dart
index f27ff6bce89f45a96d47491cf07a2611a23e16d9..726ea6f26278d1842b4d4b35a3efdbb5e7cb93e6 100644
--- a/lib/src/runner/browser/post_message_channel.dart
+++ b/lib/src/runner/browser/post_message_channel.dart
@@ -2,7 +2,6 @@
 // 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 'dart:convert';
 import 'dart:html';
 
 import 'package:stream_channel/stream_channel.dart';
diff --git a/test/io.dart b/test/io.dart
index 331a220b38545ad6cf5213663178e6ec9b876fb9..b9eec58fda77f15024435de83be344343bde130d 100644
--- a/test/io.dart
+++ b/test/io.dart
@@ -8,7 +8,6 @@ library test.test.io;
 
 import 'dart:async';
 import 'dart:io';
-import 'dart:isolate';
 
 import 'package:package_resolver/package_resolver.dart';
 import 'package:path/path.dart' as p;
@@ -134,12 +133,11 @@ ScheduledProcess runTest(List<String> args, {String reporter,
 /// Runs Dart.
 ScheduledProcess runDart(List<String> args, {Map<String, String> environment,
     String description}) {
-  var allArgs = Platform.executableArguments
-      .where((arg) =>
-          !arg.startsWith("--package-root=") && !arg.startsWith("--packages="))
-      .toList()
-      ..add(PackageResolver.current.processArgument)
-      ..addAll(args);
+  var allArgs = <Object>[]
+    ..addAll(Platform.executableArguments.where((arg) =>
+        !arg.startsWith("--package-root=") && !arg.startsWith("--packages=")))
+    ..add(PackageResolver.current.processArgument)
+    ..addAll(args);
 
   return new ScheduledProcess.start(
       p.absolute(Platform.resolvedExecutable), allArgs,