diff --git a/aux-etc-nixos/configuration.nix b/aux-etc-nixos/configuration.nix
index e1a4697..8310f36 100644
--- a/aux-etc-nixos/configuration.nix
+++ b/aux-etc-nixos/configuration.nix
@@ -167,5 +167,9 @@ in
     StreamLocalBindUnlink yes
     '';
 
+  nix.binaryCachePublicKeys = ["nixbld.m-labs.hk-1:5aSRVA5b320xbNvu30tqxVPXpld73bhtOeH6uAjRyHc="];
+  nix.binaryCaches = ["https://nixbld.m-labs.hk" "https://cache.nixos.org"];
+  nix.trustedUsers = ["sb"];
+
   system.stateVersion = "22.05";
 }