Mac updates its macOS (previously Mac OS X) desktop and laptop operating system once a year, like clockwork, bringing new features and improvements. That's all very well, but the latest version of MacOS, known as Mojave, won't run on any Mac older than 2012. Which may well mean that your Mac can't be updated, unless you follow this tutorial.
Before you go ahead and follow the advice below, a word of warning. There is a reason why Apple choosese not to support the new Mac operating system on older Macs. Older Macs just don't have the necessary components or power required to cope with the demands of the more modern systems. So if you do install Mojave, or any recent version of macOS on an old Mac, be it High Sierra, Sierra or something else, don't expect it to run smoothly.
Apple advises that macOS Mojave will run on the following Macs:
- Mac models from 2012 or later
- iMac Pro (from 2017)
- MacBook models from 2015 or later
- MacBook Pro models from 2012 or later
- MacBook Air models from 2012 or later
- Mac mini models from 2012 or later
- Mac Pro models from late 2013 (plus mid-2010 and mid-2012 models with recommended Metal-capable GPU)
That means that if your Mac is older than 2012 it won't officially be able to run Mojave. That includes most of the old-style Mac Pro models (unless you have upgraded the GPU inside).
macOS High Sierra has a little more scope. Apple said that would run happily on a late 2009 or later MacBook or iMac, or a 2010 or later MacBook Air, MacBook Pro, Mac mini or Mac Pro.
The problem is that if you've got an older Mac then the Mac App Store simply won't let you install the upgrade file.
But all is not lost. A patch tool written by a developer known as DOSDude1 enables you to install macOS Mojave on an older Mac. DOSDude1 wrote a similar patch for High Sierra and prior to that Sierra. With the patch installed you can go back as far as early 2008 models. It's unlikely to run like a dream, which is why Apple advises against this course of action. But you should be able to achieve tolerable performance.
For information about Apple's terms and conditions for using Mojave read: Should you agree to Apple's terms and conditions
How to update an old Mac
This hack doesn't work with every Mac, but many are covered, predominantly those released after 2008. You can see if your Mac is supported here.
Other than one of the supported Macs listed at the link above, you'll need the macOS Mojave Patch Tool, a copy of macOS Mojave - which you will need to download from the Mac App Store on a Mac that can support Mojave - and a USB drive with a capacity of at least 16GB.
You can download the Mojave Patch Tool here.
The macOS Mojave Patch Tool is free to download - but if you find the tool useful we would encourage you to donate to the developer.
To install the Mojave Patch Tool and run Mojave on your old Mac we advise that you follow the full step-by-step tutorial on DOSDude1.com. But here's a super-brief summary of what you'll be doing.
- First of all you need to format your USB drive as Mac OS Extended (Journaled) using Disk Utility.
- Open the macOS Mojave Patch Tool, navigate to the Mojave Installer App, select your USB drive and hit Start Operation. Boot from the USB drive.
- If you want to do a clean install, you'll need to open Disk Utility again when the installer boots, then erase the disk or partition you want to put Mojave on - this time you have the choice of using Mac OS Extended (Journaled), or the new APFS filesystem type. (You shoudl only use APFS if your target drive is a SSD, plus if you use APFS you will not have a bootable Recovery partition - there is more detail about this on DOSDude1's page).
- Install macOS normally, then reboot back on to the installer drive. This time, open the macOS Post Install application and select the correct model of Mac. Select the appropriate volume and choose Patch, then Reboot when it's finished.
- When it reboots, your Mac should now boot into a fully working copy of macOS Mojave.
Why you shouldn't install MacOS Mojave on an old Mac
We'd advise tech beginners against attempting this workaround: it calls for a moderate degree of tech expertise.
Remember that we're going against Apple's official advice on this one, which means that if something goes wrong - and that's always a possibility with an OS install, even if you're using official software - your warranty is unlikely to save you. Of course, it's unlikely that your 2008 Mac would be under any warranty so that may not worry you too much.
Back up your Mac before going any further. And bear in mind two more caveats.
Installing macOS Mojave via the Patch Tool will stop Wi-Fi working if your Mac has a Broadcom BCM4321 module - which includes certain configurations of the MacPro3,1, MacBook5,2, MacBookPro4,1, iMac8,1, Macmini3,1, and MacBookAir2,1.
Dosdude1 suggests installing a new compatible WiFi card in your machine if this is the case. To find out if you have the unsupported card open the System Profiler in About This Mac > System Report and scroll down to WiFi.
At some point Apple may patch this hack and prevent it working in future. So if you're keen, and happy that the risks and difficulties are worth it for you, then jump in while you still can.
Otherwise, you might want to read How to sell an old Mac. Alternatively here's how to run an old version of Mac OS X on a newer Mac.