diff --git a/CHANGES.md b/CHANGES.md
index 5ee168ce85..1f992a53b8 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -10,6 +10,9 @@ To be released.
 
 ### Backward-incompatible API changes
 
+ -  (Libplanet.Store) Removed unused `HashNode.Serailize()` method.
+    [[#3922], [#3924]]
+
 ### Backward-incompatible network protocol changes
 
 ### Backward-incompatible storage format changes
@@ -18,12 +21,18 @@ To be released.
 
 ### Behavioral changes
 
+ -  (Libplanet.Store) Optimized `HashNode.ToBencodex()` method.
+    [[#3922], [#3924]]
+
 ### Bug fixes
 
 ### Dependencies
 
 ### CLI tools
 
+[#3922]: https://github.com/planetarium/libplanet/issues/3922
+[#3924]: https://github.com/planetarium/libplanet/pull/3924
+
 
 Version 5.2.0
 -------------