diff --git a/src/zsh_completion/_firejail.in b/src/zsh_completion/_firejail.in
index f3090b31c77..6ce71aed8e0 100644
--- a/src/zsh_completion/_firejail.in
+++ b/src/zsh_completion/_firejail.in
@@ -105,7 +105,7 @@ _firejail_args=(
     '--keep-config-pulse[disable automatic ~/.config/pulse init]'
     '--keep-dev-shm[/dev/shm directory is untouched (even with --private-dev)]'
     '--keep-var-tmp[/var/tmp directory is untouched]'
-    '--machine-id[spoof /etc/machine-id]'
+    '--machine-id[spoof /etc/machine-id with a random id]'
     '--memory-deny-write-execute[seccomp filter to block attempts to create memory mappings that are both writable and executable]'
     '*--mkdir=-[create a directory]:'
     '*--mkfile=-[create a file]:'