diff --git a/tacker/db/migration/alembic_migrations/versions/7186440a306b_change_type_for_instance_id_of_vnf_table.py b/tacker/db/migration/alembic_migrations/versions/7186440a306b_change_type_for_instance_id_of_vnf_table.py
new file mode 100644
index 000000000..a00ce97e5
--- /dev/null
+++ b/tacker/db/migration/alembic_migrations/versions/7186440a306b_change_type_for_instance_id_of_vnf_table.py
@@ -0,0 +1,36 @@
+# Copyright 2020 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.
+#
+
+"""change type for instance_id of vnf table
+
+Revision ID: 7186440a306b
+Revises: df26c5871f3c
+Create Date: 2020-12-21 16:08:23.438871
+
+"""
+
+from alembic import op
+import sqlalchemy as sa
+
+# revision identifiers, used by Alembic.
+revision = '7186440a306b'
+down_revision = 'df26c5871f3c'
+
+
+def upgrade(active_plugins=None, options=None):
+    op.alter_column('vnf',
+                    'instance_id',
+                    type_=sa.String(length=12800),
+                    nullable=True)
diff --git a/tacker/db/migration/alembic_migrations/versions/HEAD b/tacker/db/migration/alembic_migrations/versions/HEAD
index b557bb945..2c26318e3 100644
--- a/tacker/db/migration/alembic_migrations/versions/HEAD
+++ b/tacker/db/migration/alembic_migrations/versions/HEAD
@@ -1 +1 @@
-df26c5871f3c
+7186440a306b