diff --git a/packages/sqlalchemy-spanner/tests/mockserver_tests/mock_server_test_base.py b/packages/sqlalchemy-spanner/tests/mockserver_tests/mock_server_test_base.py
index e44e9c8c841c..3795e0dca409 100644
--- a/packages/sqlalchemy-spanner/tests/mockserver_tests/mock_server_test_base.py
+++ b/packages/sqlalchemy-spanner/tests/mockserver_tests/mock_server_test_base.py
@@ -13,13 +13,12 @@
 # limitations under the License.
 import logging
 
-from google.cloud.spanner_dbapi.parsed_statement import AutocommitDmlMode
-from sqlalchemy import Engine, create_engine
-from sqlalchemy.testing.plugin.plugin_base import fixtures
-import google.cloud.spanner_v1.types.type as spanner_type
 import google.cloud.spanner_v1.types.result_set as result_set
+import google.cloud.spanner_v1.types.type as spanner_type
+import grpc
 from google.api_core.client_options import ClientOptions
 from google.auth.credentials import AnonymousCredentials
+from google.cloud.spanner_dbapi.parsed_statement import AutocommitDmlMode
 from google.cloud.spanner_v1 import (
     Client,
     ResultSet,
@@ -27,11 +26,13 @@
 )
 from google.cloud.spanner_v1.database import Database
 from google.cloud.spanner_v1.instance import Instance
-import grpc
+from sqlalchemy import Engine, create_engine
+from sqlalchemy.testing.plugin.plugin_base import fixtures
+
+from tests.mockserver_tests.mock_database_admin import DatabaseAdminServicer
 
 # TODO: Replace this with the mock server in the Spanner client lib
 from tests.mockserver_tests.mock_spanner import SpannerServicer, start_mock_server
-from tests.mockserver_tests.mock_database_admin import DatabaseAdminServicer
 
 
 def add_result(sql: str, result: ResultSet):
@@ -161,9 +162,11 @@ def teardown_method(self):
         MockServerTestBase.database_admin_service.clear_requests()
 
     def create_engine(self) -> Engine:
+        from sqlalchemy.pool import NullPool
         return create_engine(
             "spanner:///projects/p/instances/i/databases/d",
             connect_args={"client": self.client, "logger": MockServerTestBase.logger},
+            poolclass=NullPool,  # Disable pooling to force new sessions for every test
         )
 
     @property