uninstall - Delete Ubuntu from dual boot Windows 8.1 in GPT disk

I'm using Windows dual booting with Ubuntu.

I have uninstalled, and at that time my disk was formated as MBR. After deleting all partitions of Ubuntu I choose to rebuild the MBR in my disk. That way I was sure not to loose the Windows boot loader.

Now I'm using a GPT disk. I want to delete Ubuntu but I'm scared I will loose my Windows boot loader.