1 files changed, 2 insertions, 7 deletions
diff --git a/lib/modules.nix b/lib/modules.nix
index 48ddb31508f25..1e48f54407989 100644
--- a/lib/modules.nix
+++ b/lib/modules.nix
@@ -113,10 +113,6 @@ rec {
                   args ? {}
                 , # This would be remove in the future, Prefer _module.check option instead.
                   check ? true
-                  # Internal variable to avoid `_key` collisions regardless
-                  # of `extendModules`. Used in `submoduleWith`.
-                  # Test case: lib/tests/modules, "168767"
-                , extensionOffset ? 0
                 }:
     let
       withWarnings = x:
@@ -345,17 +341,15 @@ rec {
         modules ? [],
         specialArgs ? {},
         prefix ? [],
-        extensionOffset ? length modules,
         }:
           evalModules (evalModulesArgs // {
             modules = regularModules ++ modules;
             specialArgs = evalModulesArgs.specialArgs or {} // specialArgs;
             prefix = extendArgs.prefix or evalModulesArgs.prefix or [];
-            inherit extensionOffset;
           });
 
       type = lib.types.submoduleWith {
-        inherit modules specialArgs extensionOffset;
+        inherit modules specialArgs;
       };
 
       result = withWarnings {
@@ -468,6 +462,7 @@ rec {
           config = addFreeformType (addMeta (m.config or {}));
         }
     else
+      lib.throwIfNot (isAttrs m) "module ${file} (${key}) does not look like a module."
       { _file = toString m._file or file;
         key = toString m.key or key;
         disabledModules = m.disabledModules or [];