diff --git a/keystone/assignment/V8_role_backends/sql.py b/keystone/assignment/V8_role_backends/sql.py
index 3c707aa84c..b6533bdee5 100644
--- a/keystone/assignment/V8_role_backends/sql.py
+++ b/keystone/assignment/V8_role_backends/sql.py
@@ -77,4 +77,4 @@ class RoleTable(sql.ModelBase, sql.DictBase):
     id = sql.Column(sql.String(64), primary_key=True)
     name = sql.Column(sql.String(255), unique=True, nullable=False)
     extra = sql.Column(sql.JsonBlob())
-    __table_args__ = (sql.UniqueConstraint('name'), {})
+    __table_args__ = (sql.UniqueConstraint('name'),)
diff --git a/keystone/assignment/role_backends/sql.py b/keystone/assignment/role_backends/sql.py
index 347b012143..a4b769f5dd 100644
--- a/keystone/assignment/role_backends/sql.py
+++ b/keystone/assignment/role_backends/sql.py
@@ -195,4 +195,4 @@ class RoleTable(sql.ModelBase, sql.DictBase):
     domain_id = sql.Column(sql.String(64), nullable=False,
                            server_default=NULL_DOMAIN_ID)
     extra = sql.Column(sql.JsonBlob())
-    __table_args__ = (sql.UniqueConstraint('name', 'domain_id'), {})
+    __table_args__ = (sql.UniqueConstraint('name', 'domain_id'),)
diff --git a/keystone/catalog/backends/sql.py b/keystone/catalog/backends/sql.py
index 523935d1fe..c923b1302e 100644
--- a/keystone/catalog/backends/sql.py
+++ b/keystone/catalog/backends/sql.py
@@ -588,4 +588,4 @@ class ProjectEndpointGroupMembership(sql.ModelBase, sql.ModelDictMixin):
                                    nullable=False)
     project_id = sql.Column(sql.String(64), nullable=False)
     __table_args__ = (sql.PrimaryKeyConstraint('endpoint_group_id',
-                                               'project_id'), {})
+                                               'project_id'),)
diff --git a/keystone/endpoint_policy/backends/sql.py b/keystone/endpoint_policy/backends/sql.py
index 484444f126..b2687f1444 100644
--- a/keystone/endpoint_policy/backends/sql.py
+++ b/keystone/endpoint_policy/backends/sql.py
@@ -32,7 +32,7 @@ class PolicyAssociation(sql.ModelBase, sql.ModelDictMixin):
     service_id = sql.Column(sql.String(64), nullable=True)
     region_id = sql.Column(sql.String(64), nullable=True)
     __table_args__ = (sql.UniqueConstraint('endpoint_id', 'service_id',
-                                           'region_id'), {})
+                                           'region_id'),)
 
     def to_dict(self):
         """Returns the model's attributes as a dictionary.
diff --git a/keystone/identity/backends/sql.py b/keystone/identity/backends/sql.py
index 8eecd77ebe..786b87daa4 100644
--- a/keystone/identity/backends/sql.py
+++ b/keystone/identity/backends/sql.py
@@ -33,7 +33,7 @@ class User(sql.ModelBase, sql.DictBase):
     default_project_id = sql.Column(sql.String(64))
     # Unique constraint across two columns to create the separation
     # rather than just only 'name' being unique
-    __table_args__ = (sql.UniqueConstraint('domain_id', 'name'), {})
+    __table_args__ = (sql.UniqueConstraint('domain_id', 'name'),)
 
     def to_dict(self, include_extra_dict=False):
         d = super(User, self).to_dict(include_extra_dict=include_extra_dict)
@@ -52,7 +52,7 @@ class Group(sql.ModelBase, sql.DictBase):
     extra = sql.Column(sql.JsonBlob())
     # Unique constraint across two columns to create the separation
     # rather than just only 'name' being unique
-    __table_args__ = (sql.UniqueConstraint('domain_id', 'name'), {})
+    __table_args__ = (sql.UniqueConstraint('domain_id', 'name'),)
 
 
 class UserGroupMembership(sql.ModelBase, sql.DictBase):
diff --git a/keystone/identity/mapping_backends/sql.py b/keystone/identity/mapping_backends/sql.py
index 61378d6502..7e5c68f0b3 100644
--- a/keystone/identity/mapping_backends/sql.py
+++ b/keystone/identity/mapping_backends/sql.py
@@ -32,7 +32,7 @@ class IDMapping(sql.ModelBase, sql.ModelDictMixin):
     # Unique constraint to ensure you can't store more than one mapping to the
     # same underlying values
     __table_args__ = (
-        sql.UniqueConstraint('domain_id', 'local_id', 'entity_type'), {})
+        sql.UniqueConstraint('domain_id', 'local_id', 'entity_type'),)
 
 
 @dependency.requires('id_generator_api')
diff --git a/keystone/resource/V8_backends/sql.py b/keystone/resource/V8_backends/sql.py
index 7582762a51..513ec96777 100644
--- a/keystone/resource/V8_backends/sql.py
+++ b/keystone/resource/V8_backends/sql.py
@@ -238,7 +238,7 @@ class Domain(sql.ModelBase, sql.DictBase):
     name = sql.Column(sql.String(64), nullable=False)
     enabled = sql.Column(sql.Boolean, default=True, nullable=False)
     extra = sql.Column(sql.JsonBlob())
-    __table_args__ = (sql.UniqueConstraint('name'), {})
+    __table_args__ = (sql.UniqueConstraint('name'),)
 
 
 class Project(sql.ModelBase, sql.DictBase):
@@ -257,4 +257,4 @@ class Project(sql.ModelBase, sql.DictBase):
                            server_default='0')
     # Unique constraint across two columns to create the separation
     # rather than just only 'name' being unique
-    __table_args__ = (sql.UniqueConstraint('domain_id', 'name'), {})
+    __table_args__ = (sql.UniqueConstraint('domain_id', 'name'),)
diff --git a/keystone/resource/backends/sql.py b/keystone/resource/backends/sql.py
index 1a52f6928e..0a1b46d36d 100644
--- a/keystone/resource/backends/sql.py
+++ b/keystone/resource/backends/sql.py
@@ -285,7 +285,7 @@ class Domain(sql.ModelBase, sql.DictBase):
     name = sql.Column(sql.String(64), nullable=False)
     enabled = sql.Column(sql.Boolean, default=True, nullable=False)
     extra = sql.Column(sql.JsonBlob())
-    __table_args__ = (sql.UniqueConstraint('name'), {})
+    __table_args__ = (sql.UniqueConstraint('name'),)
 
 
 class Project(sql.ModelBase, sql.DictBase):
@@ -318,4 +318,4 @@ class Project(sql.ModelBase, sql.DictBase):
                            server_default='0')
     # Unique constraint across two columns to create the separation
     # rather than just only 'name' being unique
-    __table_args__ = (sql.UniqueConstraint('domain_id', 'name'), {})
+    __table_args__ = (sql.UniqueConstraint('domain_id', 'name'),)