diff --git a/nixbld-etc-nixos/configuration.nix b/nixbld-etc-nixos/configuration.nix
index ceac619..a1f330c 100644
--- a/nixbld-etc-nixos/configuration.nix
+++ b/nixbld-etc-nixos/configuration.nix
@@ -191,9 +191,11 @@ in
            ''
            dnssec-policy "default";
            inline-signing yes;
+           notify explicit;
+           also-notify { 216.218.130.2; 2001:470:100::2; }; # ns1.he.net
            '';
         slaves = [
-          "213.239.220.50" "2a01:4f8:a0:7041::1"  # qnetp
+          "216.218.133.2" "2001:470:600::2" # slave.dns.he.net
         ];
       };
     };
diff --git a/nixbld-etc-nixos/named/m-labs.hk b/nixbld-etc-nixos/named/m-labs.hk
index e734576..28b9eaa 100644
--- a/nixbld-etc-nixos/named/m-labs.hk
+++ b/nixbld-etc-nixos/named/m-labs.hk
@@ -1,7 +1,7 @@
 $TTL 7200
 
 @						SOA	NS.XN--WBTZ5WPQAJ35CFXC.XN--J6W193G. sb.m-labs.hk. (
-							2023011602
+							2023012704
 							7200
 							3600
 							86400
@@ -9,7 +9,7 @@ $TTL 7200
 
 
 						NS		NS.XN--WBTZ5WPQAJ35CFXC.XN--J6W193G.
-						NS		ns1.qnetp.net.
+						NS		ns1.he.net.
 
 						A		42.200.147.171
 						AAAA	2001:470:18:629::2