diff --git a/neutron/plugins/vmware/dbexts/models.py b/neutron/plugins/vmware/dbexts/models.py
index 0c87dfa30c..3337c9f254 100644
--- a/neutron/plugins/vmware/dbexts/models.py
+++ b/neutron/plugins/vmware/dbexts/models.py
@@ -37,9 +37,8 @@ class TzNetworkBinding(model_base.BASEV2):
     binding_type = Column(Enum('flat', 'vlan', 'stt', 'gre', 'l3_ext',
                                name='tz_network_bindings_binding_type'),
                           nullable=False, primary_key=True)
-    phy_uuid = Column(String(36), primary_key=True, nullable=True)
-    vlan_id = Column(Integer, primary_key=True, nullable=True,
-                     autoincrement=False)
+    phy_uuid = Column(String(36), primary_key=True, default='')
+    vlan_id = Column(Integer, primary_key=True, autoincrement=False, default=0)
 
     def __init__(self, network_id, binding_type, phy_uuid, vlan_id):
         self.network_id = network_id
@@ -115,4 +114,4 @@ class MultiProviderNetworks(model_base.BASEV2):
                         primary_key=True)
 
     def __init__(self, network_id):
-        self.network_id = network_id
\ No newline at end of file
+        self.network_id = network_id