How to Block macOS Tahoe Update Reminders Using LuLu Firewall on macOS Sequoia

How to Prevent Forced macOS Upgrade Prompts via SoftwareUpdate Process Blocking

For users who wish to stay on macOS Sequoia and avoid upgrading to macOS Tahoe, blocking the update daemon prevents annoying upgrade notifications. Using the open-source LuLu firewall to block outbound network requests from the software update service is a highly effective method.

1. Prerequisites

• Target OS: macOS Sequoia (15.x).
• Required Tools: LuLu Firewall (Objective-See open-source application).

2. Compatibility Snapshot

• LuLu Support: Fully supported on macOS Sequoia and newer.

3. Installation Preparation

1. Download LuLu: Go to the official Objective-See website, download LuLu, and install it. Allow the network extension in System Settings.

4. EFI and config.plist Review

1. This does not apply to this case because the updates are blocked at the application level.

5. Post-Installation

1. Block update daemon: When LuLu prompts you for network access, locate the softwareupdated process (located in /System/Library/CoreServices/softwareupdated) and select Block.
2. Alternative plist method: You can also set software update options to false: sudo defaults write /Library/Preferences/com.apple.SoftwareUpdate AutomaticDownload -boolean FALSE.

6. Troubleshooting

Reported Issue: Update notifications still appear

1. Confirm block rule: Open the LuLu application, search rules for softwareupdated, and ensure the status is set to Blocked for all network scopes.

7. Dual Boot and Advanced Configuration

• This does not apply to this case because it only affects the current macOS environment.

8. Verification, Maintenance and Rollback

• Rollback: To restore updates, open LuLu rules, locate softwareupdated, and change the rule from Block to Allow.

9. References and Glossary

• softwareupdated: The macOS system background process that fetches software updates.