diff --git a/ChangeLog b/ChangeLog
index 2d8c32c7986..456f58e3d60 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2,6 +2,12 @@
 English Dolibarr ChangeLog
 --------------------------------------------------------------
 
+WARNING: Do not try to make any Dolibarr upgrade if you are running Mysql version 5.5.40.
+Mysql version 5.5.40 has a very critical bug making your data beeing definitely lost.
+You may also experience troubles with Mysql 5.5.41 with error "Lost connection" during migration.
+Upgrading to any other version or database system is abolutely required BEFORE trying to
+make a migration.
+
 
 ***** ChangeLog for 3.7 compared to 3.6.* *****
 For users: