diff --git a/watcherclient/client.py b/watcherclient/client.py
index c1b00df..d283995 100644
--- a/watcherclient/client.py
+++ b/watcherclient/client.py
@@ -182,5 +182,4 @@ def Client(version, *args, **kwargs):
     python-watcherclient's doc.
     """
     api_version, client_class = _get_client_class_and_version(version)
-    kwargs['os_infra_optim_api_version'] = api_version.get_string()
     return client_class(*args, **kwargs)