diff --git a/litellm/proxy/middleware/prometheus_auth_middleware.py b/litellm/proxy/middleware/prometheus_auth_middleware.py
index d0e38f98946..6f33963c4e1 100644
--- a/litellm/proxy/middleware/prometheus_auth_middleware.py
+++ b/litellm/proxy/middleware/prometheus_auth_middleware.py
@@ -5,7 +5,7 @@ import json
 from typing import List
 
 from fastapi import Request
-from starlette.types import ASGIApp, Receive, Scope, Send
+from starlette.types import ASGIApp, Message, Receive, Scope, Send
 
 import litellm
 from litellm.proxy._types import SpecialHeaders
@@ -43,9 +43,9 @@ class PrometheusAuthMiddleware:
             # user_api_key_auth reads the request body, which consumes ASGI `receive`.
             # Buffer those messages and replay them for the inner app; otherwise a
             # successful auth would forward an exhausted receive and /metrics hangs.
-            buffered_messages: List[dict] = []
+            buffered_messages: List[Message] = []
 
-            async def receive_for_auth() -> dict:
+            async def receive_for_auth() -> Message:
                 message = await receive()
                 buffered_messages.append(message)
                 return message
@@ -81,7 +81,7 @@ class PrometheusAuthMiddleware:
 
             replay_idx = 0
 
-            async def receive_replay() -> dict:
+            async def receive_replay() -> Message:
                 nonlocal replay_idx
                 if replay_idx < len(buffered_messages):
                     msg = buffered_messages[replay_idx]