diff --git a/Misc/NEWS.d/next/Library/2025-09-15-19-29-12.gh-issue-130567.shDEnT.rst b/Misc/NEWS.d/next/Library/2025-09-15-19-29-12.gh-issue-130567.shDEnT.rst
new file mode 100644
index 00000000000000..c194b2331e5f4a
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-09-15-19-29-12.gh-issue-130567.shDEnT.rst
@@ -0,0 +1,2 @@
+Fix possible crash in :func:`locale.strxfrm` due to a platform bug on
+macOS.
diff --git a/Modules/_localemodule.c b/Modules/_localemodule.c
index e86d5b17d1759d..cb448b14d8cd63 100644
--- a/Modules/_localemodule.c
+++ b/Modules/_localemodule.c
@@ -457,7 +457,9 @@ _locale_strxfrm_impl(PyObject *module, PyObject *str)
 
     /* assume no change in size, first */
     n1 = n1 + 1;
-    buf = PyMem_New(wchar_t, n1);
+    /* Yet another +1 is needed to work around a platform bug in wcsxfrm()
+     * on macOS. See gh-130567. */
+    buf = PyMem_New(wchar_t, n1+1);
     if (!buf) {
         PyErr_NoMemory();
         goto exit;