How to enable uBlock Origin and Manifest V2 extensions on Chrome

Google recently released Chrome 138, and with this update, uBlock Origin and other Manifest V2-based extensions have been officially disabled completely (Microsoft has done the same on Edge). Now, all MV2 extensions are permanently disabled without any clear option to re-enable them (like before). The good news is that you can still use uBlock Origin and other MV2 extensions with a few small changes to your browser.

If you already have uBlock Origin installed in Chrome, follow these instructions. If you don't have it installed, download it from the Chrome Web Store, install it in your browser, then follow these steps:

1. Open Google Chrome and go to chrome://flags .
2. Find the flag called "Temporarily unexpire M137 flags" and set it to Enabled. Note: When Chrome 139 comes out, use the flag "Temporarily unexpire M138 flags".
3. Restart your browser.
4. Go back to chrome://flags page and disable the following flags:
   1. Extension Manifest V2 Deprecation Warning Stage
   2. Extension Manifest V2 Deprecation Disabled Stage
   3. Extension Manifest V2 Deprecation Unsupported Stage
5. Enable the "Allow legacy extension manifest versions" flag. Tip: Type "MV2" into the search box on the page to find the necessary items faster.
   
    
6. Restart your browser.

Now all your Manifest V2 extensions, including uBlock Origin, should work again. It's also worth noting that after changing the above flags, you'll be able to load uBlock Origin using Developer Mode. However, with Chrome 140, Google will be removing these flags, and the only way to restore Manifest V2-based extensions will be to modify your Chrome shortcuts.

While users can still get uBlock Origin to work, it will eventually stop working completely, and there is no workaround. As a result, users will have to switch to Manifest V3-based ad blockers, such as uBlock Lite, or switch to browsers that still support Manifest V2. For example, Firefox, Opera, and Brave have no current plans to remove these extensions.

Kareem Winters

Update 05 August 2025