diff --git a/nix/nixos-module/container/yggdrasil.nix b/nix/nixos-module/container/yggdrasil.nix
index 3af5924..28e1134 100644
--- a/nix/nixos-module/container/yggdrasil.nix
+++ b/nix/nixos-module/container/yggdrasil.nix
@@ -10,6 +10,9 @@ lib.mkIf config.site.hosts.${hostName}.services.yggdrasil.enable {
     fi
   '';
 
+  boot.kernel.sysctl."net.ipv6.conf.all.forwarding" = 1;
+  # Forward traffic under the prefix.
+
   services.yggdrasil = {
     enable = true;
     persistentKeys = true;