diff --git a/lib/build-clan/module.nix b/lib/build-clan/module.nix
index 684e82669..12b8eda88 100644
--- a/lib/build-clan/module.nix
+++ b/lib/build-clan/module.nix
@@ -179,6 +179,7 @@ in
     # Merge the meta attributes from the buildClan function
     {
       inventory.modules = clan-core.clanModules;
+      inventory._legacyModules = clan-core.clanModules;
     }
     # config.inventory.meta <- config.meta
     { inventory.meta = config.meta; }
diff --git a/lib/inventory/build-inventory/interface.nix b/lib/inventory/build-inventory/interface.nix
index 318cb2e91..9d5449447 100644
--- a/lib/inventory/build-inventory/interface.nix
+++ b/lib/inventory/build-inventory/interface.nix
@@ -96,6 +96,12 @@ in
     ./assertions.nix
   ];
   options = {
+    _legacyModules = lib.mkOption {
+      internal = true;
+      visible = false;
+      default = { };
+    };
+
     options = lib.mkOption {
       internal = true;
       visible = false;
@@ -138,6 +144,28 @@ in
             };
             ```
       '';
+
+      apply =
+        moduleSet:
+        let
+          allowedNames = lib.attrNames config._legacyModules;
+        in
+        if builtins.all (moduleName: builtins.elem moduleName allowedNames) (lib.attrNames moduleSet) then
+          moduleSet
+        else
+          lib.warn ''
+            `inventory.modules` will be deprecated soon.
+
+            Please migrate the following modules into `clan.service` modules
+            and register them in `clan.modules`
+
+            ${lib.concatStringsSep "\n" (
+              map (m: "'${m}'") (lib.attrNames (lib.filterAttrs (n: _v: !builtins.elem n allowedNames) moduleSet))
+            )}
+
+            See: https://docs.clan.lol/manual/distributed-services/
+            And: https://docs.clan.lol/authoring/clanServices/
+          '' moduleSet;
     };
 
     assertions = lib.mkOption {
diff --git a/module.nix b/module.nix
new file mode 100644
index 000000000..29c75278b
--- /dev/null
+++ b/module.nix
@@ -0,0 +1,21 @@
+{ lib, ... }:
+{
+  _class = "clan.service";
+  manifest.name = "test";
+
+  roles.peer.interface =
+    { ... }:
+    {
+      options.debug = lib.mkOption { default = 1; };
+    };
+
+  roles.peer.perInstance =
+    { settings, ... }:
+    {
+      nixosModule = {
+        options.debug = lib.mkOption {
+          default = settings;
+        };
+      };
+    };
+}