diff --git a/Misc/NEWS.d/next/Library/2025-09-11-11-09-28.gh-issue-138779.TNZnLr.rst b/Misc/NEWS.d/next/Library/2025-09-11-11-09-28.gh-issue-138779.TNZnLr.rst
new file mode 100644
index 00000000000000..d54f21ffb89669
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-09-11-11-09-28.gh-issue-138779.TNZnLr.rst
@@ -0,0 +1,3 @@
+Support device numbers larger than ``2**63-1`` for the
+:attr:`~os.stat_result.st_rdev` field of the :class:`os.stat_result`
+structure.
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 50d0ff1dc2127c..1a9475b7f7caa1 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -2759,7 +2759,7 @@ _pystat_fromstructstat(PyObject *module, STRUCT_STAT *st)
     SET_ITEM(ST_BLOCKS_IDX, PyLong_FromLong((long)st->st_blocks));
 #endif
 #ifdef HAVE_STRUCT_STAT_ST_RDEV
-    SET_ITEM(ST_RDEV_IDX, PyLong_FromLong((long)st->st_rdev));
+    SET_ITEM(ST_RDEV_IDX, _PyLong_FromDev(st->st_rdev));
 #endif
 #ifdef HAVE_STRUCT_STAT_ST_GEN
     SET_ITEM(ST_GEN_IDX, PyLong_FromLong((long)st->st_gen));