diff --git a/neutron/db/migration/alembic_migrations/versions/e6b16a30d97_cisco_provider_nets.py b/neutron/db/migration/alembic_migrations/versions/e6b16a30d97_cisco_provider_nets.py
index 2e02ee9b96..8671f77e9a 100644
--- a/neutron/db/migration/alembic_migrations/versions/e6b16a30d97_cisco_provider_nets.py
+++ b/neutron/db/migration/alembic_migrations/versions/e6b16a30d97_cisco_provider_nets.py
@@ -49,6 +49,8 @@ def upgrade(active_plugins=None, options=None):
         sa.Column('network_id', sa.String(length=36), nullable=False),
         sa.Column('network_type', sa.String(length=255), nullable=False),
         sa.Column('segmentation_id', sa.Integer(), nullable=False),
+        sa.ForeignKeyConstraint(['network_id'], ['networks.id'],
+                                ondelete='CASCADE'),
         sa.PrimaryKeyConstraint('network_id')
     )