diff --git a/rhodecode/lib/dbmigrate/migrate/versioning/schema.py b/rhodecode/lib/dbmigrate/migrate/versioning/schema.py
--- a/rhodecode/lib/dbmigrate/migrate/versioning/schema.py
+++ b/rhodecode/lib/dbmigrate/migrate/versioning/schema.py
@@ -7,7 +7,7 @@ import logging
 from sqlalchemy import (Table, Column, MetaData, String, Text, Integer,
     create_engine)
 from sqlalchemy.sql import and_
-from sqlalchemy import exceptions as sa_exceptions
+from sqlalchemy import exc as sa_exceptions
 from sqlalchemy.sql import bindparam
 
 from rhodecode.lib.dbmigrate.migrate import exceptions
@@ -20,6 +20,7 @@ from rhodecode.lib.dbmigrate.migrate.ver
 
 log = logging.getLogger(__name__)
 
+
 class ControlledSchema(object):
     """A database under version control"""