diff --git a/mistral/db/sqlalchemy/migration/alembic_migrations/versions/029_workbook_empty_namespace.py b/mistral/db/sqlalchemy/migration/alembic_migrations/versions/029_workbook_empty_namespace.py
new file mode 100644
index 000000000..7eeb2674e
--- /dev/null
+++ b/mistral/db/sqlalchemy/migration/alembic_migrations/versions/029_workbook_empty_namespace.py
@@ -0,0 +1,41 @@
+# Copyright 2018 OpenStack Foundation.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""workbook_empty_namespace
+
+Revision ID: 029
+Revises: 028
+Create Date: 2018-08-08 10:30:00.727769
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '029'
+down_revision = '028'
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.sql import table, column
+
+
+def upgrade():
+    wb_def = table('workbooks_v2', column('namespace'))
+    session = sa.orm.Session(bind=op.get_bind())
+    with session.begin(subtransactions=True):
+        session.execute(
+            wb_def.update().values(namespace='').where(
+                wb_def.c.namespace == None))  # noqa
+
+    session.commit()