diff --git a/netwatch-notify b/netwatch-notify
index 966d415..7fdf5b5 100644
--- a/netwatch-notify
+++ b/netwatch-notify
@@ -16,6 +16,7 @@
 :global IfThenElse;
 :global LogPrintExit2;
 :global ParseKeyValueStore;
+:global ScriptLock;
 :global SendNotification2;
 :global SymbolForNotification;
 
@@ -47,6 +48,8 @@
   :set NetwatchNotify [ :toarray "" ];
 }
 
+$ScriptLock $0;
+
 :foreach Host in=[ / tool netwatch find where comment~"^notify," disabled=no ] do={
   :local HostVal [ / tool netwatch get $Host ];
   :local HostInfo [ $ParseKeyValueStore ($HostVal->"comment") ];