diff --git a/share/completions/mddiagnose.fish b/share/completions/mddiagnose.fish
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+# completion for mddiagnose (macOS)
+
+complete -c mddiagnose -s h -f -d 'Display help'
+complete -c mddiagnose -s d -f -d 'Ignore unknown options'
+complete -c mddiagnose -s n -f -d 'Do not reveal the resulting package in the Finder'
+complete -c mddiagnose -s r -f -d 'Avoid restricted operations such as heap'
+complete -c mddiagnose -s s -f -d 'Skip gathering system.log'
+complete -c mddiagnose -s v -f -d 'Prints version of mddiagnose'
+complete -c mddiagnose -s m -f -d 'Minimal report'
+complete -c mddiagnose -s e -r -d 'Evalute indexing information for path'
+complete -c mddiagnose -s p -r -d 'Evalute permissions information for path'
+complete -c mddiagnose -s f -r -d 'Write the diagnostic to the specified path'