diff --git a/litellm/passthrough/utils.py b/litellm/passthrough/utils.py
index ef4357d1ca2..7c2bd4b2ac1 100644
--- a/litellm/passthrough/utils.py
+++ b/litellm/passthrough/utils.py
@@ -40,7 +40,7 @@ class BasePassthroughUtils:
         request_headers: dict,
         headers: dict,
         forward_headers: Optional[bool] = False,
-    ):
+    ) -> dict:
         """
         Helper to forward headers from original request.