diff --git a/Tests/test_imagepath.py b/Tests/test_imagepath.py
index 1e291ba7c46..9f9bff85a6b 100644
--- a/Tests/test_imagepath.py
+++ b/Tests/test_imagepath.py
@@ -216,6 +216,15 @@ def test_overflow_segfault() -> None:
             x[i] = b"0" * 16
 
 
+def test_tuple_subclass_with_larger_len() -> None:
+    class LargerLen(tuple[float, ...]):
+        def __len__(self) -> int:
+            return 10
+
+    with pytest.raises(IndexError):
+        ImagePath.Path(LargerLen((0.0,)))
+
+
 def test_compact_empty_path() -> None:
     p = ImagePath.Path(0)
     assert p.compact() == 0
diff --git a/src/path.c b/src/path.c
index 16f58cf70e4..ded65e3a371 100644
--- a/src/path.c
+++ b/src/path.c
@@ -236,7 +236,16 @@ PyPath_Flatten(PyObject *data, double **pxy) {
         }
     } else if (PyTuple_Check(data)) {
         for (i = 0; i < n; i++) {
-            PyObject *op = PyTuple_GET_ITEM(data, i);
+            /* Checked access, as a subclass may report a larger __len__ */
+            PyObject *op = PyTuple_GetItem(data, i);
+            if (op == NULL) {
+                if (!PyErr_Occurred()) {
+                    /* PyPy returns NULL without setting an exception */
+                    PyErr_SetString(PyExc_IndexError, "tuple index out of range");
+                }
+                free(xy);
+                return -1;
+            }
             j = assign_item_to_array(xy, j, op);
             if (j == -1) {
                 free(xy);