diff --git a/Lib/test/test_mmap.py b/Lib/test/test_mmap.py
@@ -407,7 +407,6 @@ def test_move(self):
        m.move(0, 0, 1)
        m.move(0, 0, 0)

-
    def test_anonymous(self):
        # anonymous mmap.mmap(-1, PAGE)
        m = mmap.mmap(-1, PAGESIZE)
@@ -887,6 +886,92 @@ def test_resize_succeeds_with_error_for_second_named_mapping(self):
        self.assertEqual(m1[:data_length], data)
        self.assertEqual(m2[:data_length], data)

class LargeMmapTests(unittest.TestCase):

    def setUp(self):

diff --git a/Misc/NEWS.d/next/Library/2023-04-29-18-23-16.gh-issue-103987.sRgALL.rst b/Misc/NEWS.d/next/Library/2023-04-29-18-23-16.gh-issue-103987.sRgALL.rst
@@ -0,0 +1,2 @@
diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c
@@ -284,7 +284,8 @@ mmap_read_method(mmap_object *self,

    CHECK_VALID(NULL);
    if (!PyArg_ParseTuple(args, "|O&:read", _Py_convert_optional_to_ssize_t, &num_bytes))
-        return(NULL);

    /* silently 'adjust' out-of-range requests */
    remaining = (self->pos < self->size) ? self->size - self->pos : 0;
@@ -325,6 +326,7 @@ mmap_gfind(mmap_object *self,
            end = self->size;

        Py_ssize_t res;
        if (reverse) {
            res = _PyBytes_ReverseFind(
                self->data + start, end - start,
@@ -388,7 +390,7 @@ mmap_write_method(mmap_object *self,

    CHECK_VALID(NULL);
    if (!PyArg_ParseTuple(args, "y*:write", &data))
-        return(NULL);

    if (!is_writable(self)) {
        PyBuffer_Release(&data);
@@ -401,6 +403,7 @@ mmap_write_method(mmap_object *self,
        return NULL;
    }

    memcpy(&self->data[self->pos], data.buf, data.len);
    self->pos += data.len;
    PyBuffer_Release(&data);
@@ -420,6 +423,7 @@ mmap_write_byte_method(mmap_object *self,
    if (!is_writable(self))
        return NULL;

    if (self->pos < self->size) {
        self->data[self->pos++] = value;
        Py_RETURN_NONE;
@@ -724,6 +728,7 @@ mmap_move_method(mmap_object *self, PyObject *args)
        if (self->size - dest < cnt || self->size - src < cnt)
            goto bounds;

        memmove(&self->data[dest], &self->data[src], cnt);

        Py_RETURN_NONE;
@@ -847,6 +852,7 @@ mmap_madvise_method(mmap_object *self, PyObject *args)
        length = self->size - start;
    }

    if (madvise(self->data + start, length, option) != 0) {
        PyErr_SetFromErrno(PyExc_OSError);
        return NULL;
@@ -945,6 +951,7 @@ mmap_subscript(mmap_object *self, PyObject *item)
                "mmap index out of range");
            return NULL;
        }
        return PyLong_FromLong(Py_CHARMASK(self->data[i]));
    }
    else if (PySlice_Check(item)) {
@@ -955,6 +962,7 @@ mmap_subscript(mmap_object *self, PyObject *item)
        }
        slicelen = PySlice_AdjustIndices(self->size, &start, &stop, step);

        if (slicelen <= 0)
            return PyBytes_FromStringAndSize("", 0);
        else if (step == 1)
@@ -968,6 +976,7 @@ mmap_subscript(mmap_object *self, PyObject *item)

            if (result_buf == NULL)
                return PyErr_NoMemory();
            for (cur = start, i = 0; i < slicelen;
                 cur += step, i++) {
                result_buf[i] = self->data[cur];
@@ -1052,6 +1061,7 @@ mmap_ass_subscript(mmap_object *self, PyObject *item, PyObject *value)
                            "in range(0, 256)");
            return -1;
        }
        self->data[i] = (char) v;
        return 0;
    }
@@ -1077,6 +1087,7 @@ mmap_ass_subscript(mmap_object *self, PyObject *item, PyObject *value)
            return -1;
        }

        if (slicelen == 0) {
        }
        else if (step == 1) {