diff --git a/src/authentic2_auth_saml/backends.py b/src/authentic2_auth_saml/backends.py
index 02d9e6aaa..ca4487129 100644
--- a/src/authentic2_auth_saml/backends.py
+++ b/src/authentic2_auth_saml/backends.py
@@ -6,10 +6,10 @@ from . import app_settings
 
 
 class SAMLBackend(SAMLBackend):
-    def authenticate(self, saml_attributes, **credentials):
+    def authenticate(self, saml_attributes, request=None):
         if not app_settings.enable:
             return None
-        return super(SAMLBackend, self).authenticate(saml_attributes, **credentials)
+        return super(SAMLBackend, self).authenticate(saml_attributes=saml_attributes, request=request)
 
     def get_saml2_authn_context(self):
         # Pass AuthnContextClassRef from the previous IdP