diff --git a/tests/isolate/spawn_uri_missing_from_isolate_test.dart b/tests/isolate/spawn_uri_missing_from_isolate_test.dart
index daefc46e381..c7551d2b08f 100644
--- a/tests/isolate/spawn_uri_missing_from_isolate_test.dart
+++ b/tests/isolate/spawn_uri_missing_from_isolate_test.dart
@@ -30,13 +30,12 @@ main() {
   ReceivePort port = new ReceivePort();
   Isolate.spawn(isolate, port.sendPort);
   Completer completer = new Completer();
-  port.listen((message) {
+  port.first.then((message) {
     if (message == SUCCESS) {
       completer.complete(null);
     } else {
       completer.completeError(message);
     }
-    port.close();
   });
 
   asyncTest(() => completer.future);
diff --git a/tests/isolate/spawn_uri_missing_test.dart b/tests/isolate/spawn_uri_missing_test.dart
index c3dd4d32f4a..f342fe216bd 100644
--- a/tests/isolate/spawn_uri_missing_test.dart
+++ b/tests/isolate/spawn_uri_missing_test.dart
@@ -12,11 +12,14 @@ import 'dart:async';
 
 import 'package:async_helper/async_helper.dart';
 
+const UNEXPECTED_MESSAGE = 'Created isolate from missing file.';
+
 Future doTest() {
   return Isolate.spawnUri(Uri.base.resolve('no_such_file'), [], null)
       .then((Isolate isolate) {
-    throw 'Created isolate from missing file';
+    throw UNEXPECTED_MESSAGE;
   }).catchError((error) {
+    if (error == UNEXPECTED_MESSAGE) throw error;
     print('An error was thrown as expected');
     return null;
   });