diff --git a/lib/yggdrasil-hq.nix b/lib/yggdrasil-hq.nix
index ce92f017..21d026b3 100644
--- a/lib/yggdrasil-hq.nix
+++ b/lib/yggdrasil-hq.nix
@@ -4,7 +4,7 @@ with lib;
 let
   cfg = config.hq.yggdrasil;
   hostNameHash = builtins.hashString "sha256" config.networking.hostName;
-  hextets = map (i: substring (4 * i) (4 * (i + 1)) hostNameHash) [ 0 1 2 3 ];
+  hextets = map (i: substring (4 * i) 4 hostNameHash) [ 0 1 2 3 ];
   hostAddr = concatStringsSep ":" hextets;
 in {
   options = with types; {