diff --git a/ArduSub/ReleaseNotes.txt b/ArduSub/ReleaseNotes.txt
index 656a4fa8fb..0a6b1c75e5 100644
--- a/ArduSub/ReleaseNotes.txt
+++ b/ArduSub/ReleaseNotes.txt
@@ -1,5 +1,11 @@
 APM:Sub Release Notes:
 
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Sub 4.0.2 21-September-2020
+
+ - Fix critical error on preflight calibration
+ - Fix CI build
+
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 Sub 4.0.1 17-March-2020