diff --git a/gen_wrap.py b/gen_wrap.py
index 4a1caa9..c38ef87 100644
--- a/gen_wrap.py
+++ b/gen_wrap.py
@@ -1468,41 +1468,6 @@ def write_exposer(
             f'       isl::handle_isl_error(ctx, "isl_{meth.cls}_read_from_str");'
             '}, py::arg("s"), py::arg("context").none(true)=py::none());\n')
 
-    # Handle auto-self-downcasts. These are deprecated.
-    if not meth.is_static:
-        for basic_cls in AUTO_DOWNCASTS.get(meth.cls, []):
-            basic_overloads = meth_to_overloads.setdefault((basic_cls, meth.name), [])
-            if any(basic_meth
-                   for basic_meth in basic_overloads
-                   if (basic_meth.is_static
-                       or meth.arg_types()[1:] == basic_meth.arg_types()[1:])
-                   ):
-                continue
-
-            # These are high-traffic APIs that are manually implemented
-            # and not subject to deprecation.
-            if basic_cls == "basic_set":
-                if meth.name in ["is_params", "get_hash"]:
-                    continue
-            elif basic_cls == "basic_map" and meth.name in ["get_hash"]:
-                continue
-
-            basic_overloads.append(meth)
-
-            downcast_doc_str = (f"{doc_str}\n\nDowncast from "
-                f":class:`{to_py_class(basic_cls)}` to "
-                f":class:`{to_py_class(meth.cls)}`.")
-            escaped_doc_str = downcast_doc_str.replace(newline, escaped_newline)
-            outf.write(f"// automatic downcast to {meth.cls}\n")
-            outf.write(f'wrap_{basic_cls}.def('
-                       # Do not be tempted to pass 'arg_str' here, it will
-                       # prevent implicit conversion.
-                       # https://github.com/wjakob/nanobind/issues/1061
-                       f'"{py_name}", {func_name}'
-                       f', py::sig("def {py_name}{type_sig}")'
-                       f', "{py_name}{type_sig}\\n{escaped_doc_str}"'
-                       ');\n')
-
 # }}}
 
 
diff --git a/islpy/_monkeypatch.py b/islpy/_monkeypatch.py
index c0cdec3..a1920e5 100644
--- a/islpy/_monkeypatch.py
+++ b/islpy/_monkeypatch.py
@@ -1216,57 +1216,3 @@ def _add_functionality() -> None:
     "Map": "to_map",
     "UnionMap": "to_union_map",
 }
-
-
-def _depr_downcast_wrapper(
-            f: Callable[Concatenate[object, P], ResultT],
-        ) -> Callable[Concatenate[object, P], ResultT]:
-    doc = f.__doc__
-    assert doc is not None
-    m = _DOWNCAST_RE.search(doc)
-    assert m, doc
-    basic_cls_name = intern(m.group(1))
-    tgt_cls_name = m.group(2)
-
-    tgt_cls = cast("type", getattr(_isl, tgt_cls_name))
-    is_overload = "Overloaded function" in doc
-    msg = (f"{basic_cls_name}.{f.__name__} "
-            f"with implicit conversion of self to {tgt_cls_name} is deprecated "
-            "and will stop working in 2026. "
-            f"Explicitly convert to {tgt_cls_name}, "
-            f"using .{_TO_METHODS[tgt_cls_name]}().")
-
-    if is_overload:
-        def wrapper(self: object, *args: P.args, **kwargs: P.kwargs) -> ResultT:
-            # "Try to" detect bad invocations of, e.g., Set.union, which is
-            # an overload of normal union and UnionSet.union.
-            if (
-                    any(isinstance(arg, tgt_cls) for arg in args)
-                    or
-                    any(isinstance(arg, tgt_cls) for arg in kwargs.values())
-                    ):
-                warn(msg, DeprecationWarning, stacklevel=2)
-
-            return f(self, *args, **kwargs)
-    else:
-        def wrapper(self: object, *args: P.args, **kwargs: P.kwargs) -> ResultT:
-            warn(msg, DeprecationWarning, stacklevel=2)
-
-            return f(self, *args, **kwargs)
-    update_wrapper(wrapper, f)
-    return wrapper
-
-
-def _monkeypatch_self_downcast_deprecation():
-    for cls in ALL_CLASSES:
-        for attr_name in dir(cls):
-            val = cast("object", getattr(cls, attr_name))
-            doc = getattr(val, "__doc__", None)
-            if doc and "\nDowncast from " in doc:
-                setattr(cls, attr_name, _depr_downcast_wrapper(
-                        cast("Callable", val),  # pyright: ignore[reportMissingTypeArgument]
-                        ))
-
-
-if not os.environ.get("ISLPY_NO_DOWNCAST_DEPRECATION", None):
-    _monkeypatch_self_downcast_deprecation()