o = BIO_new(BIO_s_mem());

    BIO_printf(bio, "POST %s%s HTTP/1.0\r\n"
-               "Host: %s:%d\r\n"
+               "Host: %s:%d\r\nContent-Type: application/ocsp-request\r\n"
               "Content-Length: %d\r\n"
               "\r\n",
               uri->path, uri->query ? uri->query : "",