diff --git a/protocols/horizon/README.md b/protocols/horizon/README.md
index c6f7ba2654..54b9ed1449 100644
--- a/protocols/horizon/README.md
+++ b/protocols/horizon/README.md
@@ -17,6 +17,8 @@ For each new version we will only track changes from the previous version.
 
 #### Changes
 
+* In ["Transaction"](https://developers.stellar.org/api/horizon/resources/transactions/object),
+`result_meta_xdr` field is [now nullable](https://github.com/stellar/go/pull/5228), and will be `null` when Horizon has `SKIP_TXMETA=true` set, otherwise if Horizon is configured with `SKIP_TXMETA=false` which is default, then `result_meta_xdr` will be the same value of base64 encoded xdr.
 * Operations responses may include a `transaction` field which represents the transaction that created the operation.
 
 ### 0.15.0
diff --git a/services/horizon/CHANGELOG.md b/services/horizon/CHANGELOG.md
index 8e6364b6d2..ac6099640d 100644
--- a/services/horizon/CHANGELOG.md
+++ b/services/horizon/CHANGELOG.md
@@ -3,6 +3,11 @@
 All notable changes to this project will be documented in this
 file. This project adheres to [Semantic Versioning](http://semver.org/).
 
+## Unreleased
+
+### Breaking Changes
+- The Horizon API Transaction resource field `result_meta_xdr` is now nullable and Horizon API will set it to `null` when Horizon has been configured with `SKIP_TXMETA=true`, otherwise if Horizon is configured with `SKIP_TXMETA=false` which is default, then the API Transaction field `result_meta_xdr` will remain as-is, being the base64 encoded xdr [5228](https://github.com/stellar/go/pull/5228).
+
 ## 2.28.3
 
 ### Fixed