diff --git a/docs/testclient.md b/docs/testclient.md
index 99346af8b..d1568f1cc 100644
--- a/docs/testclient.md
+++ b/docs/testclient.md
@@ -69,6 +69,11 @@ case you should use `client = TestClient(app, raise_server_exceptions=False)`.
     not be triggered when the `TestClient` is instantiated. You can learn more about it
     [here](lifespan.md#running-lifespan-in-tests).
 
+!!! note
+
+    By default the `TestClient` uses `testclient:50000` as the host and port. 
+    To use a different client, you can pass the host and port as a tuple: `TestClient(client=(<host>, <port>)`.
+
 ### Selecting the Async backend
 
 `TestClient` takes arguments `backend` (a string) and `backend_options` (a dictionary).