diff --git a/modules/nixos/system/network/wireguard/forwarding.nix b/modules/nixos/system/network/wireguard/forwarding.nix
index 78313d7..7ea3728 100644
--- a/modules/nixos/system/network/wireguard/forwarding.nix
+++ b/modules/nixos/system/network/wireguard/forwarding.nix
@@ -14,7 +14,7 @@
         chain prerouting {
           type nat hook prerouting priority 0; policy accept;
           
-          ${concatMapStringsSep "\n" (ports:
+          ${lib.concatMapStringsSep "\n" (ports:
             let
               from = builtins.elemAt ports 0;
               to = builtins.elemAt ports 1;