diff --git a/Lib/pathlib.py b/Lib/pathlib.py
index 9f5e27b..babc443 100644
--- a/Lib/pathlib.py
+++ b/Lib/pathlib.py
@@ -329,7 +329,10 @@
                     # parent dir
                     path, _, _ = path.rpartition(sep)
                     continue
-                newpath = path + sep + name
+                if path.endswith(sep):
+                    newpath = path + name
+                else:
+                    newpath = path + sep + name
                 if newpath in seen:
                     # Already seen this path
                     path = seen[newpath]