diff --git a/oslo_db/sqlalchemy/test_migrations.py b/oslo_db/sqlalchemy/test_migrations.py
index 2f9372e..5204b85 100644
--- a/oslo_db/sqlalchemy/test_migrations.py
+++ b/oslo_db/sqlalchemy/test_migrations.py
@@ -555,6 +555,20 @@ class ModelsMigrationsSync(object):
         return self.FKInfo((fk.parent.name,), fk.column.table.name,
                            (fk.column.name,))
 
+    def filter_metadata_diff(self, diff):
+        """Filter changes before assert in test_models_sync().
+
+        Allow subclasses to whitelist/blacklist changes. By default, no
+        filtering is performed, changes are returned as is.
+
+        :param diff: a list of differences (see `compare_metadata()` docs for
+                     details on format)
+        :returns: a list of differences
+
+        """
+
+        return diff
+
     def test_models_sync(self):
         # recent versions of sqlalchemy and alembic are needed for running of
         # this test, but we already have them in requirements
@@ -580,8 +594,8 @@ class ModelsMigrationsSync(object):
             mc = alembic.migration.MigrationContext.configure(conn, opts=opts)
 
             # compare schemas and fail with diff, if it's not empty
-            diff = alembic.autogenerate.compare_metadata(mc,
-                                                         self.get_metadata())
+            diff = self.filter_metadata_diff(
+                alembic.autogenerate.compare_metadata(mc, self.get_metadata()))
             if diff:
                 msg = pprint.pformat(diff, indent=2, width=20)
                 self.fail(
diff --git a/oslo_db/tests/sqlalchemy/test_migrations.py b/oslo_db/tests/sqlalchemy/test_migrations.py
index 96e7e31..3f37502 100644
--- a/oslo_db/tests/sqlalchemy/test_migrations.py
+++ b/oslo_db/tests/sqlalchemy/test_migrations.py
@@ -245,6 +245,53 @@ class ModelsMigrationSyncMixin(test_base.DbTestCase):
         else:
             return True
 
+    def _test_models_not_sync_filtered(self):
+        self.metadata_migrations.clear()
+        sa.Table(
+            'table', self.metadata_migrations,
+            sa.Column('fk_check', sa.String(36), nullable=False),
+            sa.PrimaryKeyConstraint('fk_check'),
+            mysql_engine='InnoDB'
+        )
+
+        sa.Table(
+            'testtbl', self.metadata_migrations,
+            sa.Column('id', sa.Integer, primary_key=True),
+            sa.Column('spam', sa.String(8), nullable=True),
+            sa.Column('eggs', sa.DateTime),
+            sa.Column('foo', sa.Boolean,
+                      server_default=sa.sql.expression.false()),
+            sa.Column('bool_wo_default', sa.Boolean, unique=True),
+            sa.Column('bar', sa.BigInteger),
+            sa.Column('defaulttest', sa.Integer, server_default='7'),
+            sa.Column('defaulttest2', sa.String(8), server_default=''),
+            sa.Column('defaulttest3', sa.String(5), server_default="fake"),
+            sa.Column('defaulttest4',
+                      sa.Enum('first', 'second', name='testenum'),
+                      server_default="first"),
+            sa.Column('fk_check', sa.String(36), nullable=False),
+            sa.UniqueConstraint('spam', 'foo', name='uniq_cons'),
+            sa.ForeignKeyConstraint(['fk_check'], ['table.fk_check']),
+            mysql_engine='InnoDB'
+        )
+
+        with mock.patch.object(self, 'filter_metadata_diff') as filter_mock:
+            def filter_diffs(diffs):
+                # test filter returning only constraint related diffs
+                return [
+                    diff
+                    for diff in diffs
+                    if 'constraint' in diff[0]
+                ]
+            filter_mock.side_effect = filter_diffs
+
+            msg = six.text_type(self.assertRaises(AssertionError,
+                                self.test_models_sync))
+            self.assertNotIn('defaulttest', msg)
+            self.assertNotIn('defaulttest3', msg)
+            self.assertNotIn('remove_fk', msg)
+            self.assertIn('constraint', msg)
+
     def _test_models_not_sync(self):
         self.metadata_migrations.clear()
         sa.Table(
@@ -300,6 +347,9 @@ class ModelsMigrationsSyncMysql(ModelsMigrationSyncMixin,
     def test_models_not_sync(self):
         self._test_models_not_sync()
 
+    def test_models_not_sync_filtered(self):
+        self._test_models_not_sync_filtered()
+
 
 class ModelsMigrationsSyncPsql(ModelsMigrationSyncMixin,
                                migrate.ModelsMigrationsSync,
@@ -308,6 +358,9 @@ class ModelsMigrationsSyncPsql(ModelsMigrationSyncMixin,
     def test_models_not_sync(self):
         self._test_models_not_sync()
 
+    def test_models_not_sync_filtered(self):
+        self._test_models_not_sync_filtered()
+
 
 class TestOldCheckForeignKeys(test_base.DbTestCase):
     def setUp(self):