diff --git a/nixbld-etc-nixos/configuration.nix b/nixbld-etc-nixos/configuration.nix
index 58b3e00..a21052b 100644
--- a/nixbld-etc-nixos/configuration.nix
+++ b/nixbld-etc-nixos/configuration.nix
@@ -137,6 +137,7 @@ in
         iptables -w -A block-insecure-devices -m mac --mac-source 00:0a:35:00:01:23 -j DROP  # function generator
         iptables -w -A block-insecure-devices -m mac --mac-source 74:5b:c5:21:f1:ee -j DROP  # siglent scope #2
         iptables -w -A block-insecure-devices -m mac --mac-source 00:19:af:5b:dd:58 -j DROP  # power supply
+        iptables -w -A block-insecure-devices -m mac --mac-source 28:58:be:dc:66:1f -j DROP  # hikvision low-cost 780nm laser viewer
         iptables -w -A FORWARD -j block-insecure-devices
       '';
       extraStopCommands = ''