diff --git a/src/cnaas_nms/api/app.py b/src/cnaas_nms/api/app.py
index 6df43c40..5559d2ef 100644
--- a/src/cnaas_nms/api/app.py
+++ b/src/cnaas_nms/api/app.py
@@ -105,7 +105,7 @@ def handle_error(self, e):
     server_metadata_url=auth_settings.OIDC_CONF_WELL_KNOWN_URL,
     client_id=auth_settings.OIDC_CLIENT_ID,
     client_secret=auth_settings.OIDC_CLIENT_SECRET,
-    client_kwargs={"scope": auth_settings.OIDC_CLIENT_SCOPE},
+    client_kwargs={"scope": auth_settings.OIDC_CLIENT_SCOPE, "code_challenge_method": "S256"},
     authorize_params={"audience": auth_settings.AUDIENCE},
     response_type="code",
     response_mode="query",