diff --git a/configs/nixos/hosts/pikachu/default.nix b/configs/nixos/hosts/pikachu/default.nix
index 6bfe1a9..703c7b3 100644
--- a/configs/nixos/hosts/pikachu/default.nix
+++ b/configs/nixos/hosts/pikachu/default.nix
@@ -64,11 +64,8 @@
     pools.pikachu = { };
   };
 
-  registry.address.pikachu = {
-    self = "10.23.10.102";
-    valheim = "10.23.10.102";
-  };
-  registry.route.pikachu.valheim = {
+  registry.address.pikachu.self = "10.23.10.102";
+  registry.route.pikachu.self = {
     domain = "valheim.alexion.dev";
     udp.ports = [
       config.modules.services.games.valheim.port
diff --git a/configs/nixos/registry/address.nix b/configs/nixos/registry/address.nix
index 8a6fd91..3f4eb65 100644
--- a/configs/nixos/registry/address.nix
+++ b/configs/nixos/registry/address.nix
@@ -1,4 +1,11 @@
 { lib, ... }:
 {
   type = lib.types.str;
+
+  checks = [
+    {
+      assertion = lib.registry.predicates.uniqueValue (entry: entry.value);
+      message = "Address registry values must be unique.";
+    }
+  ];
 }