diff --git a/CHANGELOG.md b/CHANGELOG.md
index c631bb0e2..2dafdfa26 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -65,6 +65,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added `AzureRealtimeBetaLLMService` to support Azure's OpeanAI Realtime API. Added
   foundational example `19a-azure-realtime-beta.py`.
 
+### Changed
+
+- Updated the default mode for `CartesiaTTSService` and
+  `CartesiaHttpTTSService` to `sonic-2`.
+
 ## [0.0.58] - 2025-02-26
 
 ### Added