I'm trying to change notification sounds for apps like messages. I've tried to copy the .caf files using terminal, but it gives me "Operation not permitted" terminal operation not permitted

Does anyone know a way around this? I'm running macOS Sierra

Update: I have successfully moved BoxeeBox.caf to /System/Library/PrivateFrameworks/ToneLibrary.framework/Versions/A/Resources/AlertTones/New, and it shows up in that folder terminal after moving BoxeeBox.caf

It is not one of the options that messages gives me now though the options pt. 1 the options pt. 2

Do I have to change the name of BoxeeBox.caf to one of the other files in AlertTones/New's names? Or is there an apple script file that I need to add BoxeeBox.caf into?

Update: it works, I needed to put BoxeeBox.caf into AlertTones/New and replaced Bloom.caf with it, but now I'm trying to change the sound that it makes when you receive a message when that chat is open. I have already replaced ReceivedMessage.caf (as seen in the first screenshot), Default.aiff, and Recieved Message(in Applications/Messages/Contents/Resources), but it is still making the origional sound. Is there a different file that I have to replace?

  • Turns out to be a typo, I named the .aiff in Contents/Resources Recieved Message.aiff instead of Received Message.aiff
    – Sam
    Commented Oct 6, 2018 at 18:32

2 Answers 2


A feature called System Integrity Protection, which Apple introduced in El Capitan, prevents you from modifying most system files on your Mac. You can still make changes, but you need to disable System Integrity Protection first. For security reasons, this can only be done from recovery mode.

  1. Reboot your Mac into Recovery Mode by restarting your computer and holding down Command+R until the Apple logo appears on your screen.
  2. Click Utilities → Terminal.
  3. In the Terminal window, type in csrutil disable and press Enter.
  4. Restart your Mac.

You will now be able to edit any files you wish! (Just remember, with great power comes great responsibility, or something like that.)

After you've finished making changes, you can turn System Integrity Protection back on, if you want. Just repeat the above steps, except enter csrutil enable (instead of disable) in step 3.

  • I already know about SIP, and I'm pretty sure it is disabled, thanks though
    – Sam
    Commented Oct 6, 2018 at 5:03
  • It wasn't disabled, it now is though. the problem now is where to put the file, and if I need to modify anything to make it work
    – Sam
    Commented Oct 6, 2018 at 5:41
  • @Sam Replace one of the existing audio files (after backing up the original!), then select the one you replaced in System Prefs. Commented Oct 6, 2018 at 14:20

You will have to Temporary disable the SIP

Click the  menu.
Select Restart...
Hold down Command-R to boot into the Recovery System.
Click the Utilities menu and select Terminal.
Type `csrutil disable` and press return.
Close the Terminal app.
Click the  menu and select Restart....

Do what you wanted to do..

Remember there is a reason for the System Integrity Protection, so turn it back on when done.

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