diff --git a/Lib/pathlib.py b/Lib/pathlib.py
index cfa574af6e..f92029725d 100644
--- a/Lib/pathlib.py
+++ b/Lib/pathlib.py
@@ -608,8 +608,10 @@ class _PathParents(Sequence):
             return len(self._parts)
 
     def __getitem__(self, idx):
-        if idx < 0 or idx >= len(self):
+        if idx >= len(self):
             raise IndexError(idx)
+        if idx < 0:
+            idx = idx % len(self)
         return self._pathcls._from_parsed_parts(self._drv, self._root,
                                                 self._parts[:-idx - 1])