diff --git a/activemodel/CHANGELOG.md b/activemodel/CHANGELOG.md
index bd697f8dee7f3..caf77287a30d0 100644
--- a/activemodel/CHANGELOG.md
+++ b/activemodel/CHANGELOG.md
@@ -1,3 +1,9 @@
+*   Support composite identifiers in `to_key`
+
+    `to_key` avoids wrapping `#id` value into an `Array` if `#id` already an array
+
+    *Nikita Vasilevsky*
+
 *   Add `ActiveModel::Conversion.param_delimiter` to configure delimiter being used in `to_param`
 
     *Nikita Vasilevsky*
diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index b7745caf5f16b..b898aa8040910 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,9 @@
+*   Support composite identifiers in `to_key`
+
+    `to_key` avoids wrapping `#id` value into an `Array` if `#id` already an array
+
+    *Nikita Vasilevsky*
+
 *   Allow batching methods to use already loaded relation if available
 
     Calling batch methods on already loaded relations will use the records previously loaded instead of retrieving