Python FastAPI. How to disable response headers name to be converted to lower case

I am using FastAPI for building an application.
I have the place where i set some custom response headers.

There is the standard example from FastAPI docs

from fastapi import FastAPI, Response

app = FastAPI()


@app.get("/headers-and-object/")
def get_headers(response: Response):
    response.headers["X-Cat-Dog"] = "alone in the world"
    return {"message": "Hello World"}

fastapi dev test.py --host 0.0.0.0 --port 8080

When i call this, my custom header is converted to lower case (the name of the header)

curl -i "http://0.0.0.0:8080/headers-and-object/"
HTTP/1.1 200 OK
date: Fri, 08 Nov 2024 11:43:54 GMT
server: uvicorn
content-length: 25
content-type: application/json
x-cat-dog: alone in the world

{"message":"Hello World"}

The header is “x-cat-dog” but i need it to be same as i returned “X-Cat-Dog”

is there a way to disable this behavior and have a header “as it was returned”?

I have no option to live with lower case headers. I have some JS application that reads responses and that app can not be modified and it expects a header is as. It can not find a lower case header.

Are there options?