diff --git a/bin/osv/orm.py b/bin/osv/orm.py
index dea337e35c5..3e8f869e4ea 100644
--- a/bin/osv/orm.py
+++ b/bin/osv/orm.py
@@ -1862,7 +1862,7 @@ class orm(orm_template):
                         f_pg_notnull = f_pg_def['attnotnull']
                         if isinstance(f, fields.function) and not f.store:
                             logger.notifyChannel('orm', netsvc.LOG_INFO, 'column %s (%s) in table %s removed: converted to a function !\n' % (k, f.string, self._table))
-                            cr.execute('ALTER TABLE "%s" DROP COLUMN "%s"'% (self._table, k))
+                            cr.execute('ALTER TABLE "%s" DROP COLUMN "%s" CASCADE'% (self._table, k))
                             cr.commit()
                             f_obj_type = None
                         else: