diff --git a/docs/ADVANCED_STATIC_TYPING.md b/docs/ADVANCED_STATIC_TYPING.md
index ad4a45a..16dbff4 100644
--- a/docs/ADVANCED_STATIC_TYPING.md
+++ b/docs/ADVANCED_STATIC_TYPING.md
@@ -407,7 +407,7 @@ Output:
 Method Player.add only accepts 1 argument, but this call gives 2. Remove the extra argument.
 ```
 
-Both sides of this narrow method foundation are covered by validation: `tests/typecheck_method_good.claro` checks that `DO player.add 5` is accepted, `tests/typecheck_method_bad.claro` checks the friendly wrong-type diagnostic, `tests/typecheck_method_missing_arg_bad.claro` checks the missing checked-argument diagnostic, and `tests/typecheck_method_extra_arg_bad.claro` checks the extra-argument diagnostic. Multi-method class examples are covered too, including the extra-argument case where the checked method appears after another method in the same class.
+Both sides of this narrow method foundation are covered by validation: `tests/typecheck_method_good.claro` checks that `DO player.add 5` is accepted, `tests/typecheck_method_bad.claro` checks the friendly wrong-type diagnostic, `tests/typecheck_method_missing_arg_bad.claro` checks the missing checked-argument diagnostic, and `tests/typecheck_method_extra_arg_bad.claro` checks the extra-argument diagnostic. Multi-method class examples are covered too, including the extra-argument case where the checked method appears after another method in the same class. A compatibility `CALL second.add WITH 5, 6` through a two-step alias is also covered by `tests/typecheck_object_alias_method_call_extra_arg_bad.claro`, preserving the same actionable extra-argument message for older lessons.
 
 If the method call comes before the object is created, the type checker now gives the learner the missing setup step. The modern `DO` form and the older compatibility `CALL ... WITH` form both get this guidance, even when the method name is also a typo:
 
diff --git a/docs/CURRENT_STATUS.md b/docs/CURRENT_STATUS.md
index 396cf66..67b2df2 100644
--- a/docs/CURRENT_STATUS.md
+++ b/docs/CURRENT_STATUS.md
@@ -57,6 +57,7 @@ Ready now:
 - a narrow function/method argument check: `CHECK TYPE parameter IS TYPE` inside a function or simple object method lets `claro typecheck` accept correct checked calls, catch mismatched `DO`, `CALL ... WITH`, `DO object.method ...`, and compatibility `CALL object.method WITH ...` arguments, including checked methods that appear after another method in the same class, report missing checked function and method arguments, report missing unchecked arguments for simple functions and simple object methods, treat empty compatibility calls such as `CALL greet WITH` as missing-argument mistakes, catch extra arguments to simple functions and checked methods even when the checked method appears after another method in the same class, catch modern `DO` and compatibility `CALL ... WITH` calls to undeclared simple functions, explain when `DO object.method ...` or compatibility `CALL object.method WITH ...` happens before the object is created with `NEW` even if the method name is also wrong, and catch modern plus compatibility calls to undeclared object methods with a class-specific `TEACH` hint
 - a narrow object-field assignment/check-type check for simple `NEW Class object` plus direct `SET object.field value` and `CHECK TYPE object.field IS TYPE` cases when the class declares `HAS field TYPE`; validation now covers correct NUMBER, TEXT, and YESNO direct assignments, explicitly typed field assignments, dedicated positive NUMBER/TEXT/YESNO `CHECK TYPE` metadata fixtures, simple and chained object aliases for both field assignments and `CHECK TYPE` metadata (including a chained TEXT-field check), aliased object-method calls including chained aliases in modern `DO` and compatibility `CALL ... WITH` forms (with a dedicated positive modern `DO` chained-alias fixture), field-to-field, compound arithmetic field expressions, and arithmetic/text expression result types, negative NUMBER/TEXT/YESNO field `CHECK TYPE` metadata mismatches, NUMBER/TEXT/YESNO-expectation unknown-field `CHECK TYPE` diagnostics, missing-object field assignment and `CHECK TYPE` diagnostics, NUMBER/TEXT/YESNO wrong-type diagnostics, field collection when a `HAS` field appears after a simple method, NUMBER/TEXT/YESNO-valued unknown-field diagnostics for direct assignments to undeclared fields including explicitly typed assignments, numeric and text results from simple arithmetic/text expressions in object-field assignments, plus a plain beginner-facing unknown-field diagnostic when the assigned expression type is not inferable yet
 
+
 Still needed:
 - Keep the focused typecheck validator's fixture list complete as new positive and negative examples are added. `claro validate` now executes the complete focused fixture matrix as well, so release validation cannot silently omit a listed typecheck example.
 - The expression checker now carries a known TEXT operand through all arithmetic operators so object-field diagnostics do not hide addition, subtraction, multiplication, or division mistakes; focused numeric-subtraction, numeric-division, and numeric-multiplication positives plus text-operand addition, subtraction, multiplication, and division negatives protect this behavior. Text concatenation into a TEXT field has focused positive fixtures for both operand orders, including concatenation of two TEXT object fields. Each numeric operator names the text operand and explains that it needs NUMBER values.
diff --git a/tests/test_validate_typecheck_diagnostics.py b/tests/test_validate_typecheck_diagnostics.py
index bd4f150..38830ea 100644
--- a/tests/test_validate_typecheck_diagnostics.py
+++ b/tests/test_validate_typecheck_diagnostics.py
@@ -28,6 +28,10 @@ class ValidateTypecheckDiagnosticsTests(unittest.TestCase):
             "tests/typecheck_object_alias_method_do_good.claro",
             MODULE.EXPECTED_OK,
         )
+    def test_has_compatibility_chained_alias_method_extra_arg_fixture(self):
+        self.assertTrue(
+            (ROOT / "tests/typecheck_object_alias_method_call_extra_arg_bad.claro").exists()
+        )
 
     def test_includes_dedicated_yesno_field_check_success_fixture(self):
         self.assertIn(
diff --git a/tests/typecheck_object_alias_method_call_extra_arg_bad.claro b/tests/typecheck_object_alias_method_call_extra_arg_bad.claro
new file mode 100644
index 0000000..86238a6
--- /dev/null
+++ b/tests/typecheck_object_alias_method_call_extra_arg_bad.claro
@@ -0,0 +1,12 @@
+CLASS Player
+    HAS score NUMBER
+
+    TEACH add points
+        CHECK TYPE points IS NUMBER
+    END
+END
+
+NEW Player player
+SET alias player
+SET second alias
+CALL second.add WITH 5, 6
diff --git a/tools/validate_typecheck_diagnostics.py b/tools/validate_typecheck_diagnostics.py
index 7731bc0..98dade4 100644
--- a/tools/validate_typecheck_diagnostics.py
+++ b/tools/validate_typecheck_diagnostics.py
@@ -212,6 +212,9 @@ EXPECTED = {
     "tests/typecheck_object_alias_method_call_bad.claro": [
         "tests/typecheck_object_alias_method_call_bad.claro:12: Type mismatch for method Player.add: parameter points needs NUMBER, but this argument looks like TEXT.",
     ],
+    "tests/typecheck_object_alias_method_call_extra_arg_bad.claro": [
+        "tests/typecheck_object_alias_method_call_extra_arg_bad.claro:12: Method Player.add only accepts 1 argument, but this call gives 2. Remove the extra argument.",
+    ],
 }
 
 EXPECTED_OK = [