diff --git a/python/ndtiff/nd_tiff_current.py b/python/ndtiff/nd_tiff_current.py
index f6497f0..0df2cfc 100644
--- a/python/ndtiff/nd_tiff_current.py
+++ b/python/ndtiff/nd_tiff_current.py
@@ -569,7 +569,7 @@ def _read_single_index_entry(self, data, entries, position=0):
 
     def read_index(self, path):
         print("\rReading index...          ", end="")
-        with self.file_io.open(path + os.sep + "NDTiff.index", "rb") as index_file:
+        with self.file_io.open(path + "NDTiff.index", "rb") as index_file:
             data = index_file.read()
         entries = {}
         position = 0