diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1ec076b26e..0f34b74a70 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@ FEATURES:
 
  * **New Resource:**  `aws_api_gateway_usage_plan` [GH-12542]
  * **New Resource:**  `aws_api_gateway_usage_plan_key` [GH-12851]
+ * **New Interpolation:** `substr` [GH-12870]
 
 IMPROVEMENTS: