diff --git a/odoo/fields.py b/odoo/fields.py
index 28b2088eec4268d96fb49acecb3a9b043bd042f8..195cc269d7f1b9d2077c2a38a192790683790e63 100644
--- a/odoo/fields.py
+++ b/odoo/fields.py
@@ -1003,7 +1003,7 @@ class Field(MetaField('DummyField', (object,), {})):
             except psycopg2.OperationalError:
                 _schema.error("Unable to add index for %s", self)
         else:
-            sql.drop_index(model._cr, indexname, model._table)
+            _schema.info("Keep unexpected index %s on table %s", indexname, model._table)
 
     def update_db_related(self, model):
         """ Compute a stored related field directly in SQL. """