diff --git a/Doc/library/os.rst b/Doc/library/os.rst
index acd525b453e..92b24ac9dc3 100644
--- a/Doc/library/os.rst
+++ b/Doc/library/os.rst
@@ -1285,17 +1285,17 @@ as internal buffering of data.
    .. versionadded:: 3.3
 
 
-.. function:: utimensat(dirfd, path, (atime_sec, atime_nsec), (mtime_sec, mtime_nsec), flags)
-              utimensat(dirfd, path, None, None, flags)
+.. function:: utimensat(dirfd, path[, atime=(atime_sec, atime_nsec), mtime=(mtime_sec, mtime_nsec), flags=0])
 
    Updates the timestamps of a file with nanosecond precision.
-   The second form sets *atime* and *mtime* to the current time.
+   The *atime* and *mtime* tuples default to ``None``, which sets those
+   values to the current time.
    If *atime_nsec* or *mtime_nsec* is specified as :data:`UTIME_NOW`, the corresponding
    timestamp is updated to the current time.
    If *atime_nsec* or *mtime_nsec* is specified as :data:`UTIME_OMIT`, the corresponding
    timestamp is not updated.
    If *path* is relative, it is taken as relative to *dirfd*.
-   *flags* is optional and may be 0 or :data:`AT_SYMLINK_NOFOLLOW`.
+   *flags* is optional and may be 0 (the default) or :data:`AT_SYMLINK_NOFOLLOW`.
    If *path* is relative and *dirfd* is the special value :data:`AT_FDCWD`, then *path*
    is interpreted relative to the current working directory.
 
diff --git a/Lib/test/test_posix.py b/Lib/test/test_posix.py
index cb334775c73..cdd1108b350 100644
--- a/Lib/test/test_posix.py
+++ b/Lib/test/test_posix.py
@@ -815,11 +815,16 @@ class PosixTester(unittest.TestCase):
         try:
             now = time.time()
             posix.utimensat(f, support.TESTFN, None, None)
+            posix.utimensat(f, support.TESTFN)
+            posix.utimensat(f, support.TESTFN, flags=os.AT_SYMLINK_NOFOLLOW)
             self.assertRaises(TypeError, posix.utimensat, f, support.TESTFN, (None, None), (None, None))
             self.assertRaises(TypeError, posix.utimensat, f, support.TESTFN, (now, 0), None)
             self.assertRaises(TypeError, posix.utimensat, f, support.TESTFN, None, (now, 0))
             posix.utimensat(f, support.TESTFN, (int(now), int((now - int(now)) * 1e9)),
                     (int(now), int((now - int(now)) * 1e9)))
+            posix.utimensat(dirfd=f, path=support.TESTFN,
+                            atime=(int(now), int((now - int(now)) * 1e9)),
+                            mtime=(int(now), int((now - int(now)) * 1e9)))
         finally:
             posix.close(f)
 
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index da42f3a287a..49d11822785 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -10019,12 +10019,13 @@ posix_unlinkat(PyObject *self, PyObject *args)
 
 #ifdef HAVE_UTIMENSAT
 PyDoc_STRVAR(posix_utimensat__doc__,
-"utimensat(dirfd, path, (atime_sec, atime_nsec),\n\
-    (mtime_sec, mtime_nsec), flags)\n\
+"utimensat(dirfd, path[, atime=(atime_sec, atime_nsec),\n\
+    mtime=(mtime_sec, mtime_nsec), flags=0])\n\
 utimensat(dirfd, path, None, None, flags)\n\n\
 Updates the timestamps of a file with nanosecond precision. If path is\n\
 relative, it is taken as relative to dirfd.\n\
-The second form sets atime and mtime to the current time.\n\
+If atime and mtime are both None, which is the default, set atime and\n\
+mtime to the current time.\n\
 flags is optional and may be 0 or AT_SYMLINK_NOFOLLOW.\n\
 If path is relative and dirfd is the special value AT_FDCWD, then path\n\
 is interpreted relative to the current working directory.\n\
@@ -10033,16 +10034,19 @@ current time.\n\
 If *_nsec is specified as UTIME_OMIT, the timestamp is not updated.");
 
 static PyObject *
-posix_utimensat(PyObject *self, PyObject *args)
+posix_utimensat(PyObject *self, PyObject *args, PyObject *kwargs)
 {
     PyObject *opath;
     char *path;
     int res, dirfd, flags = 0;
-    PyObject *atime, *mtime;
+    PyObject *atime = Py_None;
+    PyObject *mtime = Py_None;
+
+    static char *kwlist[] = {"dirfd", "path", "atime", "mtime", "flags", NULL};
 
     struct timespec buf[2];
 
-    if (!PyArg_ParseTuple(args, "iO&OO|i:utimensat",
+    if (!PyArg_ParseTupleAndKeywords(args, kwargs, "iO&|OOi:utimensat", kwlist,
             &dirfd, PyUnicode_FSConverter, &opath, &atime, &mtime, &flags))
         return NULL;
     path = PyBytes_AsString(opath);
@@ -10939,7 +10943,8 @@ static PyMethodDef posix_methods[] = {
     {"unlinkat",        posix_unlinkat, METH_VARARGS, posix_unlinkat__doc__},
 #endif
 #ifdef HAVE_UTIMENSAT
-    {"utimensat",       posix_utimensat, METH_VARARGS, posix_utimensat__doc__},
+    {"utimensat",       posix_utimensat, METH_VARARGS | METH_KEYWORDS,
+                        posix_utimensat__doc__},
 #endif
 #ifdef HAVE_MKFIFOAT
     {"mkfifoat",        posix_mkfifoat, METH_VARARGS, posix_mkfifoat__doc__},