diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst
index ff7772ef1ffa3b..c1dd22a85ed60e 100644
--- a/Doc/whatsnew/3.13.rst
+++ b/Doc/whatsnew/3.13.rst
@@ -473,3 +473,10 @@ Removed
   * or :c:func:`PyGILState_Ensure` and :c:func:`PyGILState_Release`.
 
   (Contributed by Victor Stinner in :gh:`105182`.)
+
+* Remove the old private, undocumented and untested ``_PyGC_FINALIZED()`` macro
+  which was kept for backward compatibility with Python 3.8 and older: use
+  :c:func:`PyObject_GC_IsFinalized()` instead. The `pythoncapi-compat project
+  <https://github.com/python/pythoncapi-compat/>`_ can be used to get this
+  function on Python 3.8 and older.
+  (Contributed by Victor Stinner in :gh:`105268`.)
diff --git a/Include/cpython/objimpl.h b/Include/cpython/objimpl.h
index 5a8cdd57c7845b..58a30aeea6ac64 100644
--- a/Include/cpython/objimpl.h
+++ b/Include/cpython/objimpl.h
@@ -78,14 +78,6 @@ PyAPI_FUNC(void) PyObject_SetArenaAllocator(PyObjectArenaAllocator *allocator);
 PyAPI_FUNC(int) PyObject_IS_GC(PyObject *obj);
 
 
-/* Code built with Py_BUILD_CORE must include pycore_gc.h instead which
-   defines a different _PyGC_FINALIZED() macro. */
-#ifndef Py_BUILD_CORE
-   // Kept for backward compatibility with Python 3.8
-#  define _PyGC_FINALIZED(o) PyObject_GC_IsFinalized(o)
-#endif
-
-
 // Test if a type supports weak references
 PyAPI_FUNC(int) PyType_SUPPORTS_WEAKREFS(PyTypeObject *type);
 
diff --git a/Misc/NEWS.d/next/C API/2023-06-06-10-57-18.gh-issue-105268.OTJUko.rst b/Misc/NEWS.d/next/C API/2023-06-06-10-57-18.gh-issue-105268.OTJUko.rst
new file mode 100644
index 00000000000000..bdabfc8c203f6e
--- /dev/null
+++ b/Misc/NEWS.d/next/C API/2023-06-06-10-57-18.gh-issue-105268.OTJUko.rst	
@@ -0,0 +1,3 @@
+Remove the old private, undocumented and untested ``_PyGC_FINALIZED()`` macro
+which was kept for backward compatibility with Python 3.8 and older. Patch by
+Victor Stinner.