diff --git a/neutron/db/models_v2.py b/neutron/db/models_v2.py
index 5067f8ae330..a93676198db 100644
--- a/neutron/db/models_v2.py
+++ b/neutron/db/models_v2.py
@@ -132,7 +132,7 @@ class Port(model_base.BASEV2, HasId, HasTenant):
     name = sa.Column(sa.String(attr.NAME_MAX_LEN))
     network_id = sa.Column(sa.String(36), sa.ForeignKey("networks.id"),
                            nullable=False)
-    fixed_ips = orm.relationship(IPAllocation, backref='ports', lazy='joined')
+    fixed_ips = orm.relationship(IPAllocation, backref='port', lazy='joined')
     mac_address = sa.Column(sa.String(32), nullable=False)
     admin_state_up = sa.Column(sa.Boolean(), nullable=False)
     status = sa.Column(sa.String(16), nullable=False)
diff --git a/neutron/plugins/ml2/plugin.py b/neutron/plugins/ml2/plugin.py
index f3f8b2ab38c..6656a88d290 100644
--- a/neutron/plugins/ml2/plugin.py
+++ b/neutron/plugins/ml2/plugin.py
@@ -884,7 +884,7 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
                                          "having IP allocation on subnet "
                                          "%(subnet)s, cannot delete"),
                                      {'ip': user_alloc.ip_address,
-                                      'port_id': user_alloc.ports.id,
+                                      'port_id': user_alloc.port_id,
                                       'subnet': id})
                             raise exc.SubnetInUse(subnet_id=id)
                         else:
@@ -915,7 +915,7 @@ class Ml2Plugin(db_base_plugin_v2.NeutronDbPluginV2,
                     data = {attributes.PORT:
                             {'fixed_ips': [{'subnet_id': ip.subnet_id,
                                             'ip_address': ip.ip_address}
-                                           for ip in a.ports.fixed_ips
+                                           for ip in a.port.fixed_ips
                                            if ip.subnet_id != id]}}
                     try:
                         self.update_port(context, a.port_id, data)