diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index 292c148e..12c4680f 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -1,3 +1,6 @@
+### 5.3.0
+- merge "PartIndex" branch into master
+
 ### 5.3.0-prerelease015
 - changed System.Collections.Immutable and System.Text.Json to '>= 6.0.0' (from '~> 6.0.0')
 - updated dotnet-tools