diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index 1487ab6..a45d93b 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -1,3 +1,6 @@
+### 5.2.1
+- updated to Aardvark.Rendering 5.3
+
 ### 5.2.0
 - updated to Aardvark 5.2