diff --git a/zaqarclient/auth/keystone.py b/zaqarclient/auth/keystone.py
index 55297597..8b568f7a 100644
--- a/zaqarclient/auth/keystone.py
+++ b/zaqarclient/auth/keystone.py
@@ -34,7 +34,6 @@ class KeystoneAuth(base.AuthBackend):
             - os_auth_token
             - os_region_name
             - os_service_type
-            - os_service_type
             - os_endpoint_type
     :type conf: `dict`
     """