diff --git a/backend/open_webui/config.py b/backend/open_webui/config.py
index 6ece5e71e..da52926cf 100644
--- a/backend/open_webui/config.py
+++ b/backend/open_webui/config.py
@@ -848,6 +848,7 @@ def load_oauth_providers():
     OAUTH_PROVIDERS["letta"] = {
         "redirect_uri": LETTA_REDIRECT_URI.value or "https://chatlettacom-production.up.railway.app/oauth/letta/callback",
         "register": letta_oauth_register,
+        "sub_claim": "id",  # Letta returns "id" instead of "sub"
     }
 
     configured_providers = ["Letta"]  # Always include Letta