bump version to 0.5.3
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9cda2a9..5adedc2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,4 @@
-## upcoming
+## 0.5.3
 
 * fix zigzag function so all coded buffer reader tests work on dart2js.
 
diff --git a/pubspec.yaml b/pubspec.yaml
index 0a13f21..d67c605 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: protobuf
-version: 0.5.2
+version: 0.5.3
 author: Dart Team <misc@dartlang.org>
 description: Runtime library for protobuf support.
 homepage: https://github.com/dart-lang/dart-protobuf