diff --git a/tests/test_types.py b/tests/test_types.py
new file mode 100644
index 00000000..a035dde0
--- /dev/null
+++ b/tests/test_types.py
@@ -0,0 +1,48 @@
+import tomlkit
+
+from tomlkit.items import Array
+from tomlkit.items import Table
+
+
+def test_custom_list_add_returns_combined_items() -> None:
+    arr = tomlkit.array()
+    arr.extend([1, 2, 3])
+
+    result = arr + [4, 5]  # noqa: RUF005 (exercising __add__ itself)
+
+    assert result == [1, 2, 3, 4, 5]
+
+
+def test_custom_list_iadd_mutates_in_place_and_keeps_wrapper_type() -> None:
+    arr = tomlkit.array()
+    arr.extend([1, 2])
+    original_id = id(arr)
+
+    arr += [9]
+
+    assert arr == [1, 2, 9]
+    assert isinstance(arr, Array)
+    assert id(arr) == original_id
+
+
+def test_custom_dict_or_returns_new_table_with_merged_items() -> None:
+    table = tomlkit.table()
+    table["a"] = 1
+    table["b"] = 2
+
+    result = table | {"c": 3}
+
+    assert dict(result) == {"a": 1, "b": 2, "c": 3}
+    assert isinstance(result, Table)
+    assert result is not table
+
+
+def test_custom_dict_ior_mutates_in_place() -> None:
+    table = tomlkit.table()
+    table["x"] = 1
+    original_id = id(table)
+
+    table |= {"y": 2}
+
+    assert dict(table) == {"x": 1, "y": 2}
+    assert id(table) == original_id
diff --git a/tomlkit/_types.py b/tomlkit/_types.py
index 3585d56c..5f5f66c1 100644
--- a/tomlkit/_types.py
+++ b/tomlkit/_types.py
@@ -12,7 +12,6 @@
     "_CustomFloat",
     "_CustomInt",
     "_CustomList",
-    "wrap_method",
 ]
 
 if TYPE_CHECKING:  # pragma: no cover
@@ -31,13 +30,8 @@
     from builtins import float as _CustomFloat
     from builtins import int as _CustomInt
     from builtins import list as _CustomList
-    from typing import Callable
-    from typing import Concatenate
-    from typing import ParamSpec
     from typing import Protocol
 
-    P = ParamSpec("P")
-
     class WrapperType(Protocol):
         def _new(self: WT, value: Any) -> WT: ...
 
@@ -76,15 +70,3 @@ class _CustomInt(Integral, int):
 
     class _CustomFloat(Real, float):
         """Adds Real mixin while pretending to be a builtin float"""
-
-
-def wrap_method(
-    original_method: Callable[Concatenate[WT, P], Any],
-) -> Callable[Concatenate[WT, P], Any]:
-    def wrapper(self: WT, /, *args: P.args, **kwargs: P.kwargs) -> Any:
-        result = original_method(self, *args, **kwargs)
-        if result is NotImplemented:
-            return result
-        return self._new(result)
-
-    return wrapper