diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1e33983..6547449 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -62,6 +62,10 @@
 * Removed `Observable{List|Map}.NONE` (not Dart2 compatible).
 * Fix issue with type in `ObservableList._notifyListChange`. cl/182284033
 
+## 0.21.0+1-dev
+
+* Updated one of observable's tests to comply with dart 2 voidness semantics
+
 ## 0.20.4+3
 
 * Support the latest release of `pkg/quiver` (0.27).
diff --git a/pubspec.yaml b/pubspec.yaml
index c448cfb..ea6c9e6 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: observable
-version: 0.21.0
+version: 0.21.0+1-dev
 author: Dart Team <misc@dartlang.org>
 description: Support for marking objects as observable
 homepage: https://github.com/dart-lang/observable
diff --git a/test/observable_test.dart b/test/observable_test.dart
index af4d9c3..3a05e2d 100644
--- a/test/observable_test.dart
+++ b/test/observable_test.dart
@@ -9,7 +9,7 @@
 
 import 'observable_test_utils.dart';
 
-main() => observableTests();
+void main() => observableTests();
 
 void observableTests() {
   // Track the subscriptions so we can clean them up in tearDown.