diff --git a/spanner/google/cloud/spanner_v1/database.py b/spanner/google/cloud/spanner_v1/database.py
index edddbc3eca15..ed571c192d05 100644
--- a/spanner/google/cloud/spanner_v1/database.py
+++ b/spanner/google/cloud/spanner_v1/database.py
@@ -254,7 +254,7 @@ def reload(self):
         response = api.get_database_ddl(self.name, metadata=metadata)
         self._ddl_statements = tuple(response.statements)
 
-    def update_ddl(self, ddl_statements, operation_id=''):
+    def update_ddl(self, ddl_statements, operation_id=""):
         """Update DDL for this database.
 
         Apply any configured schema from :attr:`ddl_statements`.
diff --git a/spanner/tests/system/test_system.py b/spanner/tests/system/test_system.py
index ab35fc901017..1cd0ca2a7ea5 100644
--- a/spanner/tests/system/test_system.py
+++ b/spanner/tests/system/test_system.py
@@ -334,10 +334,10 @@ def test_update_database_ddl_with_operation_id(self):
         # We want to make sure the operation completes.
         create_op.result(240)  # raises on failure / timeout.
         # random but shortish always start with letter
-        operation_id = 'a' + str(uuid.uuid4())[:8]
+        operation_id = "a" + str(uuid.uuid4())[:8]
         operation = temp_db.update_ddl(DDL_STATEMENTS, operation_id=operation_id)
 
-        self.assertEqual(operation_id, operation.operation.name.split('/')[-1])
+        self.assertEqual(operation_id, operation.operation.name.split("/")[-1])
 
         # We want to make sure the operation completes.
         operation.result(240)  # raises on failure / timeout.
diff --git a/spanner/tests/unit/test_database.py b/spanner/tests/unit/test_database.py
index 10eedb55f68b..2f8acff354b4 100644
--- a/spanner/tests/unit/test_database.py
+++ b/spanner/tests/unit/test_database.py
@@ -599,7 +599,7 @@ def test_update_ddl_w_operation_id(self):
         pool = _Pool()
         database = self._make_one(self.DATABASE_ID, instance, pool=pool)
 
-        future = database.update_ddl(DDL_STATEMENTS, operation_id='someOperationId')
+        future = database.update_ddl(DDL_STATEMENTS, operation_id="someOperationId")
 
         self.assertIs(future, op_future)