diff --git a/Lib/test/test_dataclasses/__init__.py b/Lib/test/test_dataclasses/__init__.py
index 3b335429b98500..c3589db99a92be 100644
--- a/Lib/test/test_dataclasses/__init__.py
+++ b/Lib/test/test_dataclasses/__init__.py
@@ -3404,6 +3404,14 @@ class C:
 
             c = C('hello')
             self.assertEqual(deepcopy(c), c)
+    def test_frozen_slots_setattr(self):
+        # gh-143969: Ensure frozen+slots uses object.__setattr__
+        @dataclass(frozen=True, slots=True)
+        class A:
+            x: int
+        a = A(1)
+        with self.assertRaisesRegex(FrozenInstanceError, 'cannot assign to field'):
+            a.x = 2
 
 
 class TestSlots(unittest.TestCase):
diff --git a/Misc/NEWS.d/next/Library/2026-01-17-23-15-55.gh-issue-143969.Waq8zN.rst b/Misc/NEWS.d/next/Library/2026-01-17-23-15-55.gh-issue-143969.Waq8zN.rst
new file mode 100644
index 00000000000000..c0a0c71f21ca7c
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-01-17-23-15-55.gh-issue-143969.Waq8zN.rst
@@ -0,0 +1,2 @@
+Fixed a crash in frozen slotted dataclasses where assigning to an attribute
+could raise an internal :exc:`TypeError` instead of failing cleanly.