I'm sure I've seen this before, but I upgraded an older MBP (2011) to an SSD. I boot to a High Sierra installer that i created and format it to Apfs, but then the drive is greyed out - it states it needs HFS+ to install.

Is this because this machine does not yet have the updated firmware that allows it to install on apfs?


  • Did you create your installer on a spinning-disk machine, or an ssd one? I seem to remember there being a different installer depending what was in the machine that downloaded it.
    – s1ns3nt
    Apr 26, 2018 at 19:17
  • Yes, its the firmware update. I created the installer on ssd one. Once it had run through the installer and updated the firmware, I rebooted off the usb installer and the option to install to afps was enalbed.
    – piagetblix
    Apr 26, 2018 at 20:18
  • 1
    You can convert the system from HFS+ to APFS after the installation is complete. Apr 26, 2018 at 20:23

1 Answer 1


In some cases the volume has to be unmounted first.

Start the Mac in recovery. Select Disk Utility. Select the volume from the left. In the tool bar at the top of the main window click unmount. Now go the option to convert to APFS is no longer greyed out.

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