diff --git a/Obsolete.md b/Obsolete.md
index 3ffe06e..2e177a9 100644
--- a/Obsolete.md
+++ b/Obsolete.md
@@ -1,5 +1,6 @@
 # Starting from v0.3.0
-From this release on `col_number_format` and `col_date_type` are merged in a single `col_types` option defining the data type for each column.
+From this release on `col_number_format` and `col_date_type` are merged in a single `col_types` option defining the data type for each column. Also note the following option is no longer supported:
+- `default_date_type` (now replaced by `locale`)
 
 # Starting from v0.2.16
 In this release the legacy cookie based persistence implementation has been removed, as a result the following configuration options will no longer be supported: