diff --git a/docs/customize/authentication.md b/docs/customize/authentication.md
index 40393bfa..1d4b1b1b 100644
--- a/docs/customize/authentication.md
+++ b/docs/customize/authentication.md
@@ -618,7 +618,7 @@ from invenio_oauthclient.contrib.settings import OauthSettingsHelper
 
 
 class MyOAuthSettingsHelper(OAuthSettingsHelper):
-    def __init__():
+    def __init__(self):
         super().__init__(
             title="my plugin",
             description="a description",