open file in binary mode

diff --git a/Lib/test/test_cpickle.py b/Lib/test/test_cpickle.py
index 702e0c9b064c4059c6f89db118b9b76bdeb04cfd..3bc700b1fb8a59f1e5be8636afff9a3374306e9b 100644 (file)
--- a/Lib/test/test_cpickle.py
+++ b/Lib/test/test_cpickle.py
@@ -23,10 +23,10 @@ class BytesIOMixin:
 class FileIOMixin:
 
     def output(self):
-        return open(test_support.TESTFN, 'w+')
+        return open(test_support.TESTFN, 'wb+')
 
     def input(self, data):
-        f = open(test_support.TESTFN, 'w+')
+        f = open(test_support.TESTFN, 'wb+')
         try:
             f.write(data)
             f.seek(0)