[c#] 405 method not allowed Web API

I tried many thing to get DELETE method work (I was getting 405 method not allowed web api) , and finally I added [Route("api/scan/{id}")] to my controller and was work fine. hope this post help some one.

     // DELETE api/Scan/5
    [Route("api/scan/{id}")]
    [ResponseType(typeof(Scan))]
    public IHttpActionResult DeleteScan(int id)
    {
        Scan scan = db.Scans.Find(id);
        if (scan == null)
        {
            return NotFound();
        }

        db.Scans.Remove(scan);
        db.SaveChanges();

        return Ok(scan);
    }