diff --git a/newsfragments/405.misc.rst b/newsfragments/405.misc.rst
new file mode 100644
index 000000000..b609a3301
--- /dev/null
+++ b/newsfragments/405.misc.rst
@@ -0,0 +1 @@
+Stop using ctypes to mutate tracebacks for ``strict_exception_groups=False``'s exception collapsing.
diff --git a/src/trio/_core/_concat_tb.py b/src/trio/_core/_concat_tb.py
index 18bd11bd1..9d0291ccf 100644
--- a/src/trio/_core/_concat_tb.py
+++ b/src/trio/_core/_concat_tb.py
@@ -1,121 +1,10 @@
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, ClassVar, cast
-
-if TYPE_CHECKING:
-    from types import TracebackType
-
-################################################################
-# concat_tb
-################################################################
-
-# We need to compute a new traceback that is the concatenation of two existing
-# tracebacks. This requires copying the entries in 'head' and then pointing
-# the final tb_next to 'tail'.
-#
-# NB: 'tail' might be None, which requires some special handling in the ctypes
-# version.
-#
-# The complication here is that Python doesn't actually support copying or
-# modifying traceback objects, so we have to get creative...
-#
-# On CPython, we use ctypes. On PyPy, we use "transparent proxies".
-#
-# Jinja2 is a useful source of inspiration:
-#   https://github.com/pallets/jinja/blob/main/src/jinja2/debug.py
-
-try:
-    import tputil
-except ImportError:
-    # ctypes it is
-    # How to handle refcounting? I don't want to use ctypes.py_object because
-    # I don't understand or trust it, and I don't want to use
-    # ctypes.pythonapi.Py_{Inc,Dec}Ref because we might clash with user code
-    # that also tries to use them but with different types. So private _ctypes
-    # APIs it is!
-    import _ctypes
-    import ctypes
-
-    class CTraceback(ctypes.Structure):
-        _fields_: ClassVar = [
-            ("PyObject_HEAD", ctypes.c_byte * object().__sizeof__()),
-            ("tb_next", ctypes.c_void_p),
-            ("tb_frame", ctypes.c_void_p),
-            ("tb_lasti", ctypes.c_int),
-            ("tb_lineno", ctypes.c_int),
-        ]
-
-    def copy_tb(base_tb: TracebackType, tb_next: TracebackType | None) -> TracebackType:
-        # TracebackType has no public constructor, so allocate one the hard way
-        try:
-            raise ValueError
-        except ValueError as exc:
-            new_tb = exc.__traceback__
-            assert new_tb is not None
-        c_new_tb = CTraceback.from_address(id(new_tb))
-
-        # At the C level, tb_next either points to the next traceback or is
-        # NULL. c_void_p and the .tb_next accessor both convert NULL to None,
-        # but we shouldn't DECREF None just because we assigned to a NULL
-        # pointer! Here we know that our new traceback has only 1 frame in it,
-        # so we can assume the tb_next field is NULL.
-        assert c_new_tb.tb_next is None
-        # If tb_next is None, then we want to set c_new_tb.tb_next to NULL,
-        # which it already is, so we're done. Otherwise, we have to actually
-        # do some work:
-        if tb_next is not None:
-            _ctypes.Py_INCREF(tb_next)
-            c_new_tb.tb_next = id(tb_next)
-
-        assert c_new_tb.tb_frame is not None
-        _ctypes.Py_INCREF(base_tb.tb_frame)
-        old_tb_frame = new_tb.tb_frame
-        c_new_tb.tb_frame = id(base_tb.tb_frame)
-        _ctypes.Py_DECREF(old_tb_frame)
-
-        c_new_tb.tb_lasti = base_tb.tb_lasti
-        c_new_tb.tb_lineno = base_tb.tb_lineno
-
-        try:
-            return new_tb
-        finally:
-            # delete references from locals to avoid creating cycles
-            # see test_cancel_scope_exit_doesnt_create_cyclic_garbage
-            del new_tb, old_tb_frame
-
-else:
-    # http://doc.pypy.org/en/latest/objspace-proxies.html
-    def copy_tb(base_tb: TracebackType, tb_next: TracebackType | None) -> TracebackType:
-        # tputil.ProxyOperation is PyPy-only, and there's no way to specify
-        # cpython/pypy in current type checkers.
-        def controller(  # type: ignore[no-any-unimported]
-            operation: tputil.ProxyOperation,
-        ) -> TracebackType | None:
-            # Rationale for pragma: I looked fairly carefully and tried a few
-            # things, and AFAICT it's not actually possible to get any
-            # 'opname' that isn't __getattr__ or __getattribute__. So there's
-            # no missing test we could add, and no value in coverage nagging
-            # us about adding one.
-            if (
-                operation.opname
-                in {
-                    "__getattribute__",
-                    "__getattr__",
-                }
-                and operation.args[0] == "tb_next"
-            ) or TYPE_CHECKING:  # pragma: no cover
-                return tb_next
-            # Delegate is reverting to original behaviour
-            return operation.delegate()  # type: ignore[no-any-return]
-
-        return cast(
-            "TracebackType",
-            tputil.make_proxy(controller, type(base_tb), base_tb),
-        )  # Returns proxy to traceback
+from types import TracebackType
 
 
 # this is used for collapsing single-exception ExceptionGroups when using
-# `strict_exception_groups=False`. Once that is retired this function and its helper can
+# `strict_exception_groups=False`. Once that is retired this function can
 # be removed as well.
 def concat_tb(
     head: TracebackType | None,
@@ -131,5 +20,7 @@ def concat_tb(
         pointer = pointer.tb_next
     current_head = tail
     for head_tb in reversed(head_tbs):
-        current_head = copy_tb(head_tb, tb_next=current_head)
+        current_head = TracebackType(
+            current_head, head_tb.tb_frame, head_tb.tb_lasti, head_tb.tb_lineno
+        )
     return current_head