diff --git a/UPDATING b/UPDATING
index 9b2a985c9e7b..df9d82a47d35 100644
--- a/UPDATING
+++ b/UPDATING
@@ -5,6 +5,17 @@ they are unavoidable.
 You should get into the habit of checking this file for changes each time
 you update your ports collection, before attempting any port upgrades.
 
+20110406:
+  AFFECTS: users of lang/ocaml and related libraries/applications
+  AUTHOR: stas@FreeBSD.org
+
+  Ocaml compiler and libraries suite has been updated to 3.12.
+  There appears to be an ABI incompatibility with .cmi files
+  generated by previos compiler versions.  Though these should
+  only affect the linking process, if some application you're
+  using start to misbehave after the lang/ocaml updated you're
+  advised to rebuild this applications using the new ocaml version.
+
 20110402:
   AFFECTS: user of net-mgmt/xymon-client and net-mgmt/xymon-server
   AUTHOR: dinoex@FreeBSD.org