diff --git a/litellm/proxy/guardrails/guardrail_hooks/unified_guardrail/unified_guardrail.py b/litellm/proxy/guardrails/guardrail_hooks/unified_guardrail/unified_guardrail.py
index fa6d190c3c9..03e86c346fc 100644
--- a/litellm/proxy/guardrails/guardrail_hooks/unified_guardrail/unified_guardrail.py
+++ b/litellm/proxy/guardrails/guardrail_hooks/unified_guardrail/unified_guardrail.py
@@ -245,11 +245,9 @@ def _ensure_litellm_metadata(data: dict, user_api_key_dict: UserAPIKeyAuth) -> N
     )
 
     BaseTranslation.merge_user_api_key_metadata_into_request(
-        # cast-ok: `data` is the request payload, annotated here as a bare
-        # dict, so passing it on is an unknown argument type. _RequestData is
-        # this module's own alias for it and keeps the argument fully known
-        # without widening three signatures or naming Any again.
-        cast(_RequestData, data),
+        cast(  # cast-ok: _RequestData is this module's own alias for the bare-dict request payload
+            _RequestData, data
+        ),
         user_api_key_dict,
     )