CHANGELOG.md in statsd-instrument-2.2.0 vs CHANGELOG.md in statsd-instrument-2.2.1

@@ -3,9 +3,13 @@
 This file documents the changes between releases of this library. When creating a pull request,
 please at an entry to the "unreleased changes" section below.
 
 ### Unreleased changes
 
+### Version 2.2.1
+
+- Fix performance regression from v2.2.0
+
 ### Version 2.2.0
 
 - Add support for two new datadog specific metric types: events and service checks.
 
 ### Version 2.1.3