diff --git a/keystone/contrib/federation/backends/sql.py b/keystone/contrib/federation/backends/sql.py
index 2675c32dbd..3c25124697 100644
--- a/keystone/contrib/federation/backends/sql.py
+++ b/keystone/contrib/federation/backends/sql.py
@@ -27,7 +27,6 @@ class FederationProtocolModel(sql.ModelBase, sql.DictBase):
     idp_id = sql.Column(sql.String(64), sql.ForeignKey('identity_provider.id',
                         ondelete='CASCADE'), primary_key=True)
     mapping_id = sql.Column(sql.String(64), nullable=False)
-    __table_args__ = (sql.UniqueConstraint('id', 'idp_id'), dict())
 
     @classmethod
     def from_dict(cls, dictionary):