diff --git a/snowflake_sql_api/testing.py b/snowflake_sql_api/testing.py
index 381316c..bacd7bf 100644
--- a/snowflake_sql_api/testing.py
+++ b/snowflake_sql_api/testing.py
@@ -599,7 +599,7 @@ def make_client(
     from .client import SnowflakeClient
 
     _reject_managed_kwargs("make_client", kwargs)
-    return SnowflakeClient(
+    client = SnowflakeClient(
         account,
         user,
         private_key=_throwaway_key(),
@@ -607,6 +607,8 @@ def make_client(
         poll_interval=poll_interval,
         **kwargs,
     )
+    client._transport._owns_client = True
+    return client
 
 
 def make_async_client(
@@ -621,7 +623,7 @@ def make_async_client(
     from .aclient import AsyncSnowflakeClient
 
     _reject_managed_kwargs("make_async_client", kwargs)
-    return AsyncSnowflakeClient(
+    client = AsyncSnowflakeClient(
         account,
         user,
         private_key=_throwaway_key(),
@@ -629,6 +631,8 @@ def make_async_client(
         poll_interval=poll_interval,
         **kwargs,
     )
+    client._transport._owns_client = True
+    return client
 
 
 # ---------------------------------------------------------------------------
diff --git a/tests/conftest.py b/tests/conftest.py
index 3b16a20..506f16b 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -25,6 +25,12 @@
 PASSPHRASE = b"correct horse battery staple"
 
 
+def pytest_configure(config: pytest.Config) -> None:
+    """Load shipped testing fixtures when pytest11 entry points are unavailable."""
+    if not config.pluginmanager.hasplugin("snowflake_sql_api"):
+        config.pluginmanager.import_plugin("snowflake_sql_api.testing")
+
+
 @pytest.fixture
 def fake_account() -> str:
     """A region-suffixed account locator for auth-normalization tests."""
diff --git a/tests/test_testing.py b/tests/test_testing.py
index aa7f047..c15aed0 100644
--- a/tests/test_testing.py
+++ b/tests/test_testing.py
@@ -46,6 +46,7 @@ def test_make_client_returns_real_client() -> None:
     assert isinstance(client, SnowflakeClient)
     assert client.query_scalar("SELECT 1") == 1
     client.close()
+    assert client._transport._client.is_closed
 
 
 def test_make_client_rejects_managed_kwargs() -> None:
@@ -304,6 +305,7 @@ async def test_async_query() -> None:
     assert isinstance(client, AsyncSnowflakeClient)
     assert await client.query("SELECT id FROM t") == [{"ID": 1}, {"ID": 2}]
     await client.aclose()
+    assert client._transport._client.is_closed
 
 
 async def test_async_submit_and_result() -> None: