diff --git a/backend/open_webui/config.py b/backend/open_webui/config.py
index da52926cf..29b503318 100644
--- a/backend/open_webui/config.py
+++ b/backend/open_webui/config.py
@@ -813,16 +813,9 @@ def load_oauth_providers():
         }
 
     # Always register Letta OAuth provider (this is a Letta-focused deployment)
+    # Note: Letta returns non-standard token_type: "access_token" instead of "Bearer"
+    # This is handled manually in oauth.py _letta_token_exchange()
     def letta_oauth_register(oauth: OAuth):
-        # Letta returns token_type: "access_token" instead of "Bearer", fix it
-        def letta_compliance_fix(session):
-            def _fix_token_response(response):
-                data = response.json()
-                if data.get("token_type") == "access_token":
-                    data["token_type"] = "Bearer"
-                return data
-            session.register_compliance_hook("access_token_response", _fix_token_response)
-
         client = oauth.register(
             name="letta",
             client_id=LETTA_CLIENT_ID.value or "ci-let-1e9dae1e14b8412e0dec10aebce26da3",
@@ -841,7 +834,6 @@ def load_oauth_providers():
                 ),
             },
             redirect_uri=LETTA_REDIRECT_URI.value or "https://chatlettacom-production.up.railway.app/oauth/letta/callback",
-            compliance_fix=letta_compliance_fix,
         )
         return client
 
diff --git a/backend/open_webui/utils/oauth.py b/backend/open_webui/utils/oauth.py
index 2ccc906c6..65ebd762f 100644
--- a/backend/open_webui/utils/oauth.py
+++ b/backend/open_webui/utils/oauth.py
@@ -1331,8 +1331,13 @@ class OAuthManager:
             except Exception as e:
                 # Letta returns non-standard token_type: "access_token" instead of "Bearer"
                 # Handle this by manually exchanging the token
-                if provider == "letta" and "unsupported_token_type" in str(e):
-                    log.info("Letta OAuth: handling non-standard token_type, manually exchanging token")
+                error_str = str(e).lower()
+                if provider == "letta" and (
+                    "unsupported_token_type" in error_str
+                    or "status_code" in error_str  # compliance_fix error
+                    or "400" in error_str
+                ):
+                    log.info(f"Letta OAuth: handling token exchange error ({e}), manually exchanging token")
                     try:
                         token = await self._letta_token_exchange(request, client)
                     except Exception as letta_e: