curl_easy_setopt(curl, CURLOPT_READFUNCTION, fread_buffer);
 #ifndef NO_CURL_IOCTL
        curl_easy_setopt(curl, CURLOPT_IOCTLFUNCTION, ioctl_buffer);
-       curl_easy_setopt(curl, CURLOPT_IOCTLDATA, &buffer);
+       curl_easy_setopt(curl, CURLOPT_IOCTLDATA, buffer);
 #endif
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_fn);
        curl_easy_setopt(curl, CURLOPT_NOBODY, 0);