IMPORTANT NOTE: These steps are designed to be followed by an IT Professional, Apple Support, or other qualified individual. In following these steps, you are doing so at your own risk. Though we wanted to make these steps available to our users, the ServantPC HelpDesk cannot support rolling back your macOS.



Step 1: Always make sure you have a backup of your Mac


The rollback process will erase your hard drive entirely, meaning: any files, programs, or documents will also be erased if you don't back them up first. You can use a flash drive, external hard drive, or a cloud-based storage like DropBox, OneDrive, or iCloud to store your backup.



Step 2: Create a bootable drive of macOS Mojave


NOTE: If your Mac came with macOS Mojave, you can skip "Step 2" and "Step 3" and go to "Step 4".


Before you erase macOS Catalina from your computer, download macOS Mojave from the Mac App Store. You'll need a copy of macOS Mojave on an external hard drive in order to downgrade from macOS Catalina.


To download Mojave from the Mac App Store:


  1. Click on the App Store icon in the Dock.


  2. In the search area type macOS Mojave and click the [Get] button.



Step 3: Make a bootable installer drive for macOS Mojave.


NOTE: You may need your Administrator’s help with this.


  1. After downloading the installer, connect the USB flash drive or other volume you're using for the bootable installer. Make sure that it has at least 12GB of available storage and is formatted as Mac OS Extended.

  2. Open Terminal, which is in the Utilities folder of your Applications folder.

  3. Copy and paste the following command in Terminal:

    sudo /Applications/Install\ macOS\ Mojave.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume

    NOTE: You may need to replace the "Applications" folder with the name of the folder where you have saved the Mojave installation file, and "MyVolume" with the name of the USB flash drive or other volume you're using (if it has a different name).


  4. Press <Return> after entering the command.

  5. When prompted, type your administrator password and press <Return> again. Terminal will not show any characters as you type your password.

  6. When prompted, type "Y" to confirm that you want to erase the volume, then press <Return>. Terminal shows the progress as the bootable installer is created.

  7. When Terminal says that it's done, the volume will have the same name as the installer you downloaded, such as "Install macOS Mojave". You can now quit Terminal and eject the volume.



Important information for 2018 or newer Macs with the T2 security chip


You may need to allow booting from external media before you attempt to downgrade.

NOTE: You'll need the firmware password you used to enable the Startup Security Utility. This is different from your administrative password and your Apple ID. Make sure you know the correct password to access the Startup Security Utility before you begin.


  1. Restart your Mac.

  2. Hold down <Command>+<R> right when you see the Apple Logo-- this will put your Mac into Recovery Mode.

  3. Click Utilities in the Menu Bar.

  4. Click on Startup Security Utility.


  5. Enter your Administrator credentials.

  6. Make sure Allow booting from external media is selected.



Step 4: Erase macOS Catalina


  1. Connect your Mac to the internet via Wi-Fi or Ethernet.

  2. Click on the Apple icon in the upper left corner of the screen.

  3. Select Restart from the drop-down menu.

  4. Hold down <Command>+<R>, and keep holding the keys until your computer reboots-- this will put your computer into Recovery Mode.

  5. Click on Disk Utility in the OS X Utilities selector.

  6. Click [Continue].


  7. Select your Startup Disk.

  8. Click on the Erase tab at the top of the window.


  9. Enter a name for the file to be destroyed (e.g. "macOS Catalina").

  10. If your Mac is using HFS+, select Mac OS Extended (Journaled) from the format list. If your Mac is using APFS, select APFS from the format list.

  11. If Scheme is available, select GUID Partition Map.

  12. Click [Erase].


  13. Choose Quit Disk Utility from the drop-down menu in the upper left corner of the screen to go back to the OS X Utilities selector.

Step 5: Reinstall macOS Mojave


NOTE: If your Mac came with macOS Mojave, you can restart your Mac while holding down <Shift>+<Option>+<Command>+<R> to install the operating system that came with your Mac. Otherwise, follow the steps below to install Mojave back on your Mac.


  1. Connect your Mac to the internet via Wi-Fi or Ethernet.

  2. Plug the bootable hard drive you made with Mojave on it into your Mac.

  3. Click on the Apple icon in the upper left corner of the screen.

  4. Select Restart from the drop-down menu.

  5. Hold down <Option> while your computer restarts-- this will send you to the option to select a startup disk.

  6. Select your bootable drive with macOS Mojave from the list of startup disk options. macOS Mojave will begin installing on your Mac.

  7. Click [Continue] in the macOS Mojave installation window. macOS Mojave will install like a standard update. You will agree to the licensing terms before the software reboots on your Mac.



Step 6: Restore settings from an earlier macOS Mojave Time machine or other backup


NOTE: If you do not have a backup you will need to reinstall Servant Keeper and connect to your Cloud database or restore a backup of your Local database.