diff --git a/CHANGELOG.md b/CHANGELOG.md
index 35067d9..3675e5c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,13 @@
+## 0.4.0
+
+### Breaking Changes
+
+- None
+
+### Added
+- [#40](https://github.com/IFTTT/polo/pull/40) Support for optional 2nd instance argument
+
+
 ## 0.3.0
 
 ### Breaking Changes
diff --git a/lib/polo/version.rb b/lib/polo/version.rb
index 21772bb..c61ee57 100644
--- a/lib/polo/version.rb
+++ b/lib/polo/version.rb
@@ -1,3 +1,3 @@
 module Polo
-  VERSION = "0.3.0"
+  VERSION = "0.4.0"
 end