diff --git a/h2o-py/tests/testdir_jira/pyunit_pubdev_6339.py b/h2o-py/tests/testdir_jira/pyunit_pubdev_6339.py
index <HASH>..<HASH> 100644
--- a/h2o-py/tests/testdir_jira/pyunit_pubdev_6339.py
+++ b/h2o-py/tests/testdir_jira/pyunit_pubdev_6339.py
@@ -57,7 +57,7 @@ def calculate_chunk_size(file_path, num_cols, cores, cloud_size):
     # get maximal line size from file in bytes
     max_line_length = 0
     total_size = 0
-    with open(file_path) as input_file:
+    with open(file_path, "rU") as input_file:
         for line in input_file:
             size = len(line)
             total_size = total_size + size
PUBDEV-<I> edit loading file to be able to read universal line ends. (#<I>)