Aws S3 Only PutObject Policy

i'm trying to setup a Only PutObject policy to by bucket as following:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "Stmt####",
            "Effect": "Allow",
            "Action": [
                "s3:PutObject",
                "s3:PutObjectAcl",
                "s3:PutObjectVersionAcl"
            ],
            "Resource": [
                "arn:aws:s3:::my-bucket/*"
            ]
        }
    ]
}

However when i try to upload a file thought AWS SDK I receive a 403 response from AWS. I'm absolutely sure to use the correct access key of the IAM user that has this policy attached to it.

Anyone knows why AWS3 complain with this policy when it shouldn't?