diff --git a/CHANGELOG.md b/CHANGELOG.md
index fbf12f2..d9db81c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 1.3.3
+
+* Declare support for `async` 2.0.0.
+
 ## 1.3.2
 
 * Update to make the code work with strong-mode clean Zone API.
diff --git a/pubspec.yaml b/pubspec.yaml
index 3c65826..b9c5c8d 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,10 +1,10 @@
 name: pool
-version: 1.3.2
+version: 1.3.3
 author: Dart Team <misc@dartlang.org>
 description: A class for managing a finite pool of resources.
 homepage: https://github.com/dart-lang/pool
 dependencies:
-  async: "^1.4.0"
+  async: ">=1.4.0 <3.0.0"
   stack_trace: ">=0.9.2 <2.0.0"
 environment:
   sdk: ">=1.23.0 <2.0.0"