diff --git a/CHANGELOG.md b/CHANGELOG.md
index 755eb86..ea7fca5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.11.3+15
+
+* Declare support for `async` 2.0.0.
+
 ## 0.11.3+14
 
 * Remove single quote ("'" - ASCII 39) from boundary characters.
diff --git a/pubspec.yaml b/pubspec.yaml
index d0d56a4..b18e155 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,10 +1,10 @@
 name: http
-version: 0.11.3+14
+version: 0.11.3+15
 author: "Dart Team <misc@dartlang.org>"
 homepage: https://github.com/dart-lang/http
 description: A composable, Future-based API for making HTTP requests.
 dependencies:
-  async: "^1.10.0"
+  async: ">=1.10.0 <3.0.0"
   collection: "^1.5.0"
   http_parser: ">=0.0.1 <4.0.0"
   path: ">=0.9.0 <2.0.0"