diff --git a/src/main.py b/src/main.py
index eff6ba8..4d44d66 100644
--- a/src/main.py
+++ b/src/main.py
@@ -78,7 +78,7 @@ async def test_data(api_key: str, request: Request, size: str) -> StreamingRespo
         return StreamingResponse(
             status_code=status.HTTP_200_OK,
             content=generate_data(size, BUFFER_SIZE),
-            headers={'Content-Type': 'application/octet-stream'}
+            media_type='application/octet-stream'
         )
 
     except MinSizePerRequestError: