如何使用go和aws-sdk覆盖s3预签名PUT URL上的文件名

Question

This code works but results in a filename that when downloaded, has url encodings in its name:

var input = (&s3.PutObjectInput{}).
        SetBucket("io").
        SetKey(filePath)
        resp, _ := svc.PutObjectRequest(input)
        urlStr, err := resp.Presign(15 * time.Minute)

This input:

var input = (&s3.PutObjectInput{}).
        SetBucket("io").
        SetKey(filePath).
        SetContentDisposition("attachment; filename =\""+fileName+"\"")

results in this error message after the url is PUT: There were headers present in the request which were not signed

when I try what's suggested here before signing my request:

resp, _ := svc.PutObjectRequest(input)
resp.HTTPRequest.Header.Add("ResponseContentDisposition:","attachment; filename =\""+fileName+"\"")

I get the same error. Do you know what I'm doing wrong or is there another way to specify the file name with a presigned url?