diff --git a/tests/test_testclient.py b/tests/test_testclient.py
index 478dbca46..a68e07927 100644
--- a/tests/test_testclient.py
+++ b/tests/test_testclient.py
@@ -422,3 +422,9 @@ async def app(scope: Scope, receive: Receive, send: Send) -> None:
     with client.websocket_connect("/hello-world", params={"foo": "bar"}) as websocket:
         data = websocket.receive_bytes()
         assert data == b"/hello-world"
+
+
+def test_timeout_deprecation() -> None:
+    with pytest.deprecated_call():
+        client = TestClient(mock_service)
+        client.request("GET", "/", timeout=1)