diff --git a/cheat-sheets/Linux-and-BSD-firewalls-cheat-sheet.adoc b/cheat-sheets/Linux-and-BSD-firewalls-cheat-sheet.adoc
index 44da566..7722327 100644
--- a/cheat-sheets/Linux-and-BSD-firewalls-cheat-sheet.adoc
+++ b/cheat-sheets/Linux-and-BSD-firewalls-cheat-sheet.adoc
@@ -59,7 +59,7 @@ else helps.
 |*firewall-cmd --list-all-zones*
 |List all zones with their rules and associated interfaces.
 
-|*firewall-cmd -add-service <service name>*
+|*firewall-cmd --add-service <service name>*
 |Add predefined service by name to the default zone, with action ACCEPT, e.g. `firewall-cmd -add-service ftp` .