Declare support for async 2.0.0. (#687)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7d3e53a..22aa888 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.12.24+7
+
+* Declare support for `async` 2.0.0.
+
 ## 0.12.24+6
 
 * Small refactoring to make the package compatible with strong-mode compliant Zone API.
diff --git a/pubspec.yaml b/pubspec.yaml
index 5f6dfc3..d60c2d3 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: test
-version: 0.12.25-dev
+version: 0.12.24+7
 author: Dart Team <misc@dartlang.org>
 description: A library for writing dart unit tests.
 homepage: https://github.com/dart-lang/test
@@ -8,7 +8,7 @@
 dependencies:
   analyzer: '>=0.26.4 <0.32.0'
   args: '>=0.13.1 <2.0.0'
-  async: '^1.13.0'
+  async: '>=1.13.0 <3.0.0'
   barback: '>=0.14.0 <0.16.0'
   boolean_selector: '^1.0.0'
   collection: '^1.8.0'