diff --git a/machine/catacomb/default.nix b/machine/catacomb/default.nix
index 50a0cf9..34ec62e 100644
--- a/machine/catacomb/default.nix
+++ b/machine/catacomb/default.nix
@@ -35,7 +35,7 @@
   ];
 
   networking = {
-    hostId = "beeeeee5";
+    hostId = "beeeeee5";  # this must be consistent for ZFS
     firewall = {
       enable = true;
       allowedTCPPorts = [ 139 445 ];